TEXT: a visual encyclopedia
  
  DK PUBLISHING
  a visual encyclopedia
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  Contents
  FOREWORD
  PREHISTORIC LIFE
  How life began
  Evolution
  Timeline of life
  Changing planet 
  All about fossils
  Dinosaur National Monument
  Fossil hunting
  A look at size
  INVERTEBRATES
  What are invertebrates? 
  The first animals
  Cambrian Explosion
  Opabinia
  Marrella
  Trilobites
  Selenopeltis
  Echinoderms
  Brittle stars
  Spiders and scorpions
  Giant millipede
  Insects
  Butterfly
  Fossilized in amber
  Meganeura
  Ammonites
  Fossil gems
  Fossil seashells
  EARLY VERTEBRATES
  What are vertebrates?
  Jawless fish
  Armored fish
  Sharks and rays
  Megatooth shark
  Bony fish
  Lepidotes
  Lobe-finned fish
  Conquering land
  Amphibians 
  Amphibamus
  Early plants
  5
  6
  8
  10
  12
  14
  16
  18
  20
  22
  24
  26
  28
  30
  32
  34
  36
  38
  40
  42
  44
  46
  48
  50
  52
  54
  56
  58
  60
  62
  64
  66
  68
  70
  72
  74
  76
  78
  80
  82
  84
  86
  LONDON, NEW YORK,  
  MELBOURNE, MUNICH, and DELHI
  Senior editors  Ben Morgan, Caroline Bingham 
  Project designer  Pamela Shiels
  Editor  Wendy Horobin
   Designer  Rachael Grady
  US editor  Margaret Parrish
  Picture researcher  Frances Vargo
  Production editor  Siu Chan
  Art director  Martin Wilson 
  Category publisher  Mary Ling
    Consultant  Dr. Darren Naish
  DK India
  Managing editor  Suchismita Banerjee
  Managing art editor  Romi Chakraborty
  Senior editors  Pakshalika Jayaprakash, Kingshuk Ghoshal
  Consulting editor  Dipali Singh
  Editorial team  Parameshwari Sircar, Suefa Lee
  Senior designer  Govind Mittal
  Design team  Mahua Mandal, Pooja Pawwar, Prashant Kumar
  CTS manager  Sunil Sharma
  Creative technical support  Tarun Sharma, 
  Saurabh Challariya, Jagtar Singh, Nand Kishor Acharya
  First published in the United States in 2011 by  
  DK Publishing  
  375 Hudson Street, New York, New York 10014
  10 9 8 7 6 5 4 3 2 1 
  001–179455–Jul/11
  Copyright © 2011 Dorling Kindersley Limited
  All rights reserved under International and Pan-American 
  Copyright Conventions. No part of this publication may be  
  reproduced, stored in a retrieval system, or transmitted  
  in any form or by any means, electronic, mechanical,  
  photocopying, recording, or otherwise, without the prior  
  written permission of the copyright owner. Published  
  in Great Britain by Dorling Kindersley Limited.
  A catalog record for this book  
  is available from the Library of Congress.
  ISBN: 978-0-7566-8230-9
  Printed and bound in China by Toppan
  Discover more at 
  www.dk.com
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  Postosuchus
  Eﬃgia
  Crocodylomorphs
  Pterosaurs
  Eudimorphodon
  Nothosaurs
  Plesiosaurs
  The Loch Ness monster
  Rhomaleosaurus
  Ichthyosaurs
  Stenopterygius
  A young fossil hunter
  Mosasaurs 
  DINOSAURS AND BIRDS
  Killer jaws
  What are dinosaurs?
  Small ornithischians
  Pachycephalosaurus
  Ceratopsians
  Triceratops
  Iguanodontians
  Hadrosaurids
  Dinosaur droppings
  Corythosaurus
  Edmontosaurus
  Scelidosaurus
  Stegosaurs
  Kentrosaurus
  Ankylosaurs
  Euoplocephalus
  Prosauropods
  Sauropods and relatives
  Inside a dinosaur
  Isanosaurus
  Diplodocoids
  Barosaurus
  Building a dinosaur
  Titanosaurs
  Dinosaur tracks
  Theropods 
  Eoraptor
  Coelophysis 
  Dubreuillosaurus
  Spinosaurids
  Suchomimus
  Allosaurus
  Tyrannosauroids
  Tyrannosaurus
  Compsognathids
  Ornithomimids
  Animatronic dinosaurs
  Oviraptorosaurs
  88
  90
  92
  94
  96
  98
  100
  102
  104
  106
  108
  110
  112
  114
  116
  118
  120
  122
  124
  126
  128
  130
  132
  134
  136
  138
  140
  142
  144
  146
  148
  150
  152
  154
  156
  158
  160
  162
  164
  166
  168
  170
  172
  174
  176
  178
  180
  182
  184
  186
  188
  190
  Dinosaur eggs
  Therizinosaurs
  Dromaeosaurs
  Fight to the death
  Microraptor
  Sinornithosaurus
  Troodon
  Death of the dinosaurs
  Early birds
  Late birds
  Gastornis
  MAMMALS
  What are mammals?
  Pelycosaurs
  Therapsids
  The ﬁrst mammals
  Flowering plants
  Marsupials
  Thylacine
  Insect-eaters and relatives
  Icaronycteris
  Cats and hyenas
  Ice age!
  Caniforms
  A sticky end
  Rabbits and rodents
  Hoofed mammals
  Leptomeryx
  Macrauchenia
  Horses
  Chalicotherium
  Rhinoceroses
  Ashfall fossil beds
  Elephants and relatives
  Woolly mammoth
  Lyuba, the baby mammoth
  Megatherium
  Deer, giraﬀes, and camels
  Aurochs
  Cave paintings
  Andrewsarchus
  Whales in the making
  Primates
  Australopithecus
  Homo erectus
  Neanderthals
  Myths and legends
  Modern humans
  Bushman rock art
  GLOSSARY AND INDEX
  192
  194
  196
  198
  200
  202
  204
  206
  208
  210
  212
  214
  216
  218
  220
  222
  224
  226
  228
  230
  232
  234
  236
  238
  240
  242
  244
  246
  248
  250
  252
  254
  256
  258
  260
  262
  264
  266
  268
  270
  272
  274
  276
  278
  280
  282
  284
  286
  288
  290
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  4
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  5
  Foreword
  W
  e are surrounded by fascinating animals. Gigantic 
  whales and sharks swim in the oceans. Spectacular 
  large animals—such as big cats, elephants and giraﬀes— 
  live on the land. Wild places everywhere are ﬁlled with 
  insects, birds, and thousands of other living things. But 
  Earth’s fossil record shows us that these creatures are just 
  the tips of an amazing hidden tree of life that stretches 
  back hundreds of millions of years into the distant past. 
  This rich fossil record tells us an incredible and 
  complicated story of evolution and extinction. While 
  modern animals may well be fascinating, those of the past 
  were often bigger, stronger, or much, much weirder.
  In this beautifully illustrated book, we look in detail at the 
  huge variety of animal life that has evolved over the past 
  500 million years or so, from the origins of complex life in 
  the Precambrian age to the dinosaurs of the Mesozoic Era 
  and the mammals and birds of more modern times.
  Most of the world’s fossils represent the remains of small 
  creatures like shellﬁsh and plankton. But others show us 
  that incredible beasts—sometimes very diﬀerent from 
  living animals—once existed as well. We know of 
  crocodile-sized millipedes, horse-eating giant birds, 
  monstrous sea reptiles, and bizarre mammals like ground 
  sloths and saber-toothed cats. Figuring out what these 
  animals looked like when alive has often been a diﬃcult 
  challenge, and scientists and artists have worked hard to 
  reconstruct their appearance and behavior. 
  In this book you will see many spectacular illustrations  
  of these animals and many others, all arranged in their 
  evolutionary families and roughly in the order in which 
  they appeared. Opening this book is like stepping back in 
  time. Get ready to go on a spectacular visual tour of the 
  animal life of the past, and prepare to be amazed.
  Dr. Darren Naish
  Science writer and honorary research associate 
  at the University of Portsmouth, UK
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  6
  u THE GRAND CANYON gives us an 
  amazing glimpse back in time. As the river 
  eats deeper into ancient layers of rock, it 
  reveals fossils that formed millions or even 
  billions of years ago.
  PREHISTORIC LIFE
  PREHISTORIC
  LIFE
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  7
  Prehistoric refers to the 
  time before written records 
  began. It covers an 
  enormous period of 
  history, beginning with 
  Earth’s birth 4.6 billion 
  years ago. Enter an 
  endlessly fascinating world.
  PREHISTORIC LIFE
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  8
  How life began
  Earth ﬁrst formed about 4.6 billion years 
  ago. When the planet was very young, life 
  would have been impossible—the ground 
  was blisteringly hot and there was no water  
  in sight. So how did life begin?
  PREHISTORIC LIFE
  EARLY EARTH
  A sea of molten rock covered the 
  newly formed Earth. In time, this 
  cooled to solid rock, but volcanoes 
  continued to spew out ﬂoods of 
  lava. The volcanoes also released 
  gases from deep inside the planet, 
  forming Earth’s atmosphere, though 
  the air at ﬁrst was poisonous.
  COMETS AND ASTEROIDS
  For millions of years, Earth’s surface was 
  bombarded by comets, asteroids, and even 
  small planets. The collisions tore open the 
  planet’s newly formed crust, releasing more 
  ﬂoods of lava. But they also delivered water.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  9
  Model of a 
  DNA molecule
  Oceans form
  As the young Earth slowly cooled, 
  so did its atmosphere. Scalding steam 
  released by volcanoes condensed to 
  form liquid water that fell as rain, 
  producing a downpour that lasted as 
  long as a million years. Comets and 
  asteroids brought yet more water. All 
  the water pooled on the surface to 
  form vast oceans.
  A watery beginning
  Many scientists think life 
  began about 3.8 billion years 
  ago in the deep sea, which 
  was safer than Earth’s deadly 
  surface. The ﬁrst life-forms 
  might have lived around hot 
  volcanic vents, feeding oﬀ 
  energy-rich chemicals 
  dissolved in the boiling 
  water. Special kinds of 
  bacteria thrive in these 
  scalding habitats even today.
  Life in hot water
  At Grand Prismatic Spring in Yellowstone 
  National Park, bacteria thrive in water too hot 
  for any other organism to bear.
  Copycat molecules
  The ﬁrst life-form was not a whole organism or even a 
  cell—it was just a molecule that could make copies of 
  itself. This is what DNA does today. DNA can’t copy itself 
  outside cells, so the ﬁrst living molecule 
  must have been something diﬀerent. 
  Later on, it evolved into DNA.
  The age of bacteria
  Soon after life began, the 
  self-copying molecules built cells 
  around themselves and became bacteria. 
  Bacteria were the only forms of life on Earth 
  for the next 3 billion years, a vast span of time.
  A true survivor
  Some of the oldest evidence of life on Earth 
  comes from stromatolites. These are rocklike 
  mounds formed by colonies of bacteria. Fossil 
  stromatolites date back to 3.5 billion years 
  ago. The bacteria in stromatolites live like 
  plants, using the Sun’s energy to make food 
  and in doing so releasing oxygen. Billions  
  of years ago, they made enough oxygen to 
  transform Earth’s air, paving the way for 
  air-breathing animals to evolve.
  d WATER Life cannot exist without 
  liquid water. Today water covers 71 
  percent of the Earth’s surface.
  d LIVING STROMATOLITES 
  can still be found today, such as here  
  in Shark Bay, Western Australia.
  Bacteria are single-celled organisms 
  that are too small to see. Millions live 
  on your skin and inside your body.
  Stromatolite
  PREHISTORIC LIFE
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  10
  PREHISTORIC LIFE
  Evolution
  Fossils of prehistoric animals show us that life 
  on Earth is always changing. Over time, old 
  species disappear and new ones develop from 
  them, like new relatives appearing in a family 
  tree. These new species appear thanks to a 
  process of gradual change we call evolution.
  The giraffe’s neck
  The giraﬀe’s long neck 
  evolved because natural 
  selection weeded out 
  individuals that couldn’t 
  reach food high in the trees. With each 
  generation, the tallest giraﬀes got the most 
  food and had the most babies. Over time,  
  the species changed as its neck grew longer.
  TAKE A LOOK—A STORY OF FINCHES
  The most famous person to 
  collect evidence for the idea  
  of evolution was the English 
  naturalist Charles Darwin.  
  He visited the Galápagos Islands 
  in the 1830s, where he found a 
  range of similar ﬁnch species, each 
  with a beak suited to its particular 
  diet. He realized they’d all evolved 
  from a common ancestor that had 
  settled on the islands long ago.
  Woodpecker ﬁnch
  Camarhynchus pallidus
  Medium ground ﬁnch
  Geospiza fortis
  Vegetarian ﬁnch
  Platyspiza crassirostris
  Warbler ﬁnch
  Certhidea olivacea
  NATURAL SELECTION
  Evolution is driven by a process called natural selection. 
  Animals and plants produce more oﬀspring than survive 
  to adulthood, all of them slightly diﬀerent. Nature selects 
  those with the best characteristics, which then pass on 
  these characteristics to the next generation.
  u BREEDING FROGS 
  lay many hundreds of eggs, 
  but only a tiny number 
  will survive to become 
  adults themselves.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  11
  PREHISTORIC LIFE
  Asian 
  elephant
  (today)
  Deinotherium 
  (2 million  
  years ago)
  Gomphotherium 
  (20 million years ago)
  Phiomia 
  (35 million 
  years ago)
  Moeritherium 
  (50 million years ago)
  In a few rare examples, we can see gradual evolution in 
  fossils. The elephant belongs to a group of animals called 
  proboscideans. Over time, proboscideans became larger 
  and developed larger tusks and trunks. But the ancient 
  animals shown here may not be direct ancestors of 
  the elephant—they are merely glimpses of parts  
  of the elephant’s large and  
  hidden family 
  tree.
  An unpopular theory
  People made fun of Darwin for his  
  ideas; he was drawn with the body of a 
  chimpanzee in 1871 when he proposed 
  that humans were related to apes. 
  EVOLUTION OF THE ELEPHANT
  Artificial selection
  Darwin realized that animal 
  breeders change their breeds 
  using a process very similar to 
  natural selection. Instead of 
  letting nature choose which 
  animals will breed, breeders 
  make the choice themselves. 
  Darwin called this artiﬁcial 
  selection. All dog breeds 
  were created this way from 
  their wild ancestor, the wolf.
  FOSSIL EVIDENCE
  One reason Darwin was ridiculed is 
  that the fossil record is much too sparse to 
  show a process of gradual change. However, 
  some key fossils show clear links between 
  related animal groups. One example is 
  Archaeopteryx—a missing link between 
  dinosaurs and birds.
  d ARCHAEOPTERYX
  had feathers but also  
  teeth, claws, and a tail  
  like those of dinosaurs.
  d DOGS All domestic dogs 
  today have a common 
  ancestor in the wolf.
  Gray 
  wolf
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  12
  Timeline of life
  Earth’s history stretches back 4.6 billion years to our 
  planet’s birth. Scientists divide this vast span of time 
  into diﬀerent periods, such as the Jurassic Period, when 
  many of the dinosaurs lived. Here you can see all the 
  periods on a timeline showing the history of life.
  PREHISTORIC LIFE
  PRECAMBRIAN
  ERAS AND PERIODS
  4.6 billion to 542 
  million years ago
  CAMBRIAN
  542–488 million years ago
  ORDOVICIAN
  PALEOZOIC ERA
  488–444 million years ago
  SILURIAN
  444–416 million years ago
  DEVONIAN
  416–358 million years ago
  CARBONIFEROUS
  358–299 million years ago
  THE LINES TELL TALES
  The past leaves clues buried in the rock 
  below our feet. Certain types of rock 
  build up in layers (strata) over millions 
  of years. Diﬀerent layers correspond to 
  diﬀerent periods in Earth’s history.
  , GRAND CANYON 
  The diﬀerent periods in Earth’s 
  history are named after the layers 
  of rock in which fossils are found. 
  At the Grand Canyon, you can see 
  these ancient rock layers, which get 
  older toward the bottom.
  Dinosaurs died out
  65 million years ago.
  Earth formed  
  4.6 billion years ago.
  Plants spread onto 
  land 440 million 
  years ago.
  Invertebrates with hard 
  cases, such as trilobites, 
  appeared in the seas  
  542 million years ago.
  PRECA
  MBRIAN
  CAMBR
  IAN
  SILUR
  IAN
  O
  R
  D
  O
  V
  I
  C
  I
  A
  N
  C
  R
  E
  T
  A
  CE
  O
  U
  S
  . EARTH’S HISTORY is divided into 
  very long stretches of time called eras. 
  These are further divided into shorter 
  stretches called periods, such as the 
  Jurassic and Triassic. 
  Trilobites scuttled 
  around on the seaﬂoor 
  (see pages 36–37).
  Starﬁsh (sea stars) became 
  common in the sea (see 
  pages 40–41).
  Pseudocrinites anchored 
  itself to the seabed in the 
  late Silurian.
  Dunkleosteus, 
  a giant predator, terrorized 
  the seas (see page 68).
  Dragonﬂies and other 
  insects buzzed through the 
  air (see pages 54–55).
  Life began about  
  3.8 billion years 
  ago, perhaps in 
  the deep sea.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  PREHISTORIC LIFE
  MESOZOIC ERA
  CENOZOIC ERA
  PERMIAN
  299–251 million years ago
  TRIASSIC
  251–200 million years ago
  JURASSIC
  200–145 million years ago
  CRETACEOUS
  145–65 million years ago
  PALEOGENE
  65–23 million years ago
  NEOGENE
  23 million years ago
  Amphibians evolved from 
  ﬁsh and spread onto land 
  360 million years ago.
  Modern humans 
  appeared
  200,000 years ago.
  Birds evolved from dinosaurs
  150 million years ago.
  Mammals took over about 
  70 million years ago, after 
  dinosaurs died out.
  Dinosaurs appeared  
  230 million years ago.
  Fish (the ﬁrst 
  vertebrates) became the 
  dominant form of life 
  in the seas 400 million 
  years ago.
  DEVONI
  AN
  PERMIA
  N
  PALEOG
  EN
  E
  NEOGE
  NE
  TRIASSI
  C
  JURASSIC
  Dimetrodon was the 
  most fearsome predator  
  of its time (see page 218).
  The ﬁrst dinosaurs 
  appeared, one of the 
  earliest known being 
  Herrerasaurus.
  The ﬁrst mammals were 
  small, mouselike animals 
  (see pages 222–223).
  One of the earliest known 
  primates, Eosimias, appeared 
  in this period (see page 277).
  Our apelike 
  ancestors began 
  walking (pages 
  278–281).
  The earlies known bird, 
  Archaeopteryx, appeared 
  (see page 208).
  Ice age
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  14
  Changing 
  planet
  Planet Earth is always changing. 
  Areas of land (continents) move 
  slowly around on Earth’s surface, 
  changing the map of the world. 
  The climate swings from warm to 
  cold, and the plants and animals 
  change from one era to the next, 
  sometimes dramatically. Scientists 
  divide the age of the dinosaurs into 
  three periods, all of which were 
  very diﬀerent from today’s world.
  EARTH TODAY
  Today Earth’s land is divided into seven  
  major areas that we call continents: Europe, 
  Africa, Asia, North America, South America, 
  Antarctica, and Australasia. All the continents 
  are still moving, but very slowly—at about the 
  speed your ﬁngernails grow.
  JURASSIC LIFE
  TRIASSIC LIFE
  CRETACEOUS LIFE
  d THE JURASSIC 
  enjoyed a slightly milder 
  climate than the Triassic. 
  Dinosaurs thrived and 
  reached enormous sizes.
  Coelophysis
  Pterodactylus
  Pteranodon
  Corythosaurus
  Allosaurus
  Apatosaurus
  Triceratops
  PREHISTORIC LIFE
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  15
  Cretaceous life 
  145–65 million years ago
  The continents continued to break  
  up during the Cretaceous. As a result,  
  dinosaurs on diﬀerent continents evolved 
  in diﬀerent ways, giving rise to many  
  new species. Tyrannosaurus 
  emerged, as did Triceratops 
  and Iguanodon. Flowering 
  plants appeared; early species 
  included magnolias and passion 
  ﬂowers. Dense forests contained 
  trees we know today, such as 
  oak, maple, walnut, and beech.
  Triassic life 
  251–200 million years ago
  In the Triassic period, Earth’s land formed 
  a single continent called Pangaea. The 
  coast and river valleys were green, but 
  much of the interior was desert. There 
  were no ﬂowering plants; instead, 
  tough-leaved plants such as cycads  
  (a palmlike tree), ginkgos, 
  horsetails, and conifers 
  ﬂourished (all of which  
  are still with us). Early 
  dinosaurs included 
  Herrerasaurus, Plateosaurus, 
  Chindesaurus, Coelophysis, 
  and Eoraptor. 
  Jurassic life 
  200–145 million years ago
  Pangaea broke into two continents 
  around 200 million years ago, with 
  oceans spreading over what had been 
  land to create enormous shallow seas. 
  The Jurassic saw the emergence of  
  giant, plant-eating sauropods (such  
  as Brachiosaurus and Diplodocus) and 
  large predators (such as Allosaurus). 
  Lush forests spread across the land 
  and the deserts shrank. 
  Common plants included 
  conifers, monkey puzzle 
  trees, and ferns.
  u CRETACEOUS EARTH 
  The continents began to resemble 
  those we recognize today during  
  the Cretaceous period.
  u JURASSIC EARTH 
  Pangaea split into Laurasia in the 
  north and Gondwana in the south, 
  with shallow seas between.
  u TRIASSIC EARTH 
  Pangaea began to break up during 
  the Triassic, with the Tethys Sea  
  pushing between its two halves.
  d THE CRETACEOUS 
  was cooler still, although it  
  was warmer than today’s 
  world. Dinosaurs ruled the 
  land but pterosaurs and 
  insects ruled the air.
  , THE TRIASSIC saw 
  the planet’s ﬁrst dinosaurs, 
  all fairly small, like this 
  Coelophysis. They lived in 
  a hot, largely barren world. 
  Fern
  Magnolia
  Cycad
  Tethys Sea
  Pangaea
  Tethys Sea
  Gondwana
  Laurasia
  Africa
  Antarctica
  South 
  America
  India
  Brachiosaurus
  Stegosaurus
  Ankylosaurus
  PREHISTORIC LIFE
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  16
  PREHISTORIC LIFE
  All about fossils
  Almost everything we know about prehistoric animals 
  comes from fossils. A fossil is the preserved remains or  
  trace of an ancient animal or plant. The word “fossil” 
  comes from the Latin word fossilis. That means 
  “dug up,” and that’s how some fossils are  
  discovered, although most are exposed  
  by erosion. Most fossilized animals  
  have lain buried for millions  
  of years. 
  u IT’S IN THE DETAIL Complete fossilized 
  skeletons are rare, but when found they provide  
  a huge amount of information for fossil hunters 
  (paleontologists).
  TYPES OF FOSSIL
  Fossils can be sorted, or classiﬁed, into diﬀerent 
  types, depending on how they formed. All take 
  millions of years to form—fossilization is not quick.
  Total preservation If an insect 
  or spider was caught in the 
  sticky sap released by a tree such 
  as a pine, it may be preserved 
  complete. Creatures that are 
  millions of years old have been 
  preserved in fossilized tree resin 
  (known as amber) in this way.
  Mineralization Dinosaurs, like us, had 
  hard bones, and sometimes just these parts 
  of an animal are preserved—though not  
  as bone, which is replaced over time with 
  minerals to form rock. Rock has to be 
  carefully removed to expose the fossils.
  DID YOU KNOW?
   
  ■ Fossils are usually found in rock but may 
  also be found in mud or gravel.
   
  ■ The parts of an animal most likely to 
  fossilize are the hard parts: the bones or 
  teeth or a creature’s shell.
   
  ■ Teeth are among the most commonly 
  found fossils.
   
  ■ The oldest fossils are stromatolites 
  (mounds of rock made by sea-dwelling 
  bacteria). These have been dated to  
  3.5 billion years ago.
  A dinosaur dies and 
  falls into the muddy 
  bank of a river.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  17
  PREHISTORIC LIFE
  TAKE A LOOK—WHAT IS A PALEONTOLOGIST?
  People who study fossils are called 
  paleontologists. Paleontologists may 
  work in the ﬁeld, digging up new fossils, 
  or in labs or museums. They work like 
  detectives, carefully gathering as many 
  clues as they can to ﬁnd out what 
  happened in the past and to ﬁgure  
  out where each new discovery ﬁts in  
  the tree of life.
  Petrified Tree trunks, just like 
  bones, can be turned to rock 
  by mineralization over millions 
  of years. Petriﬁed trees still 
  look like logs. Petriﬁcation 
  means “change to stone.”
  External mold Sometimes 
  the original organism dissolves 
  completely, but leaves an 
  impression of itself in the  
  rock. This impression is  
  called a mold.
  Natural cast This forms 
  just like an external mold,  
  but the hole then ﬁlls in as 
  minerals from water slowly 
  crystallize inside it, forming  
  a rock such as ﬂint.
  Trace fossil Occasionally an 
  animal will leave a hint of its 
  presence: a trace. This may  
  be a footprint, a nest, tooth 
  marks, or even droppings. 
  These are called trace fossils.
  A SLOW PROCESS
  A fossil can only form if an animal’s body  
  is buried quickly after death, so fossilized 
  animals are animals that have died in a river  
  and have sunk into mud, for example, or  
  those that have died in a sandstorm and been 
  buried in sand. These ﬁve diagrams show  
  one way a dinosaur’s bones—in this case  
  a Baryonyx—may be fossilized and found 
  millions of years later.
  What makes a fossil?
  All kinds of living things have been 
  discovered in fossil form. We have 
  unearthed fossilized animal skeletons, 
  skin impressions, footprints, teeth, 
  animal droppings, insects, and plants. 
  The hard parts of an animal, such as the 
  bones, are the parts that fossilize best.
  The fossil has been 
  exposed and a team  
  of paleontologists is 
  working to remove it.
  Thousands of years later, the 
  glaciers have gone and the land 
  is now a barren desert.
  Millions of years later, the sea is gone 
  and the layers of rock over the fossil are 
  slowly eroded by weather and glaciers, 
  bringing the fossil back to the surface.
  A sea has spread over the area, and new 
  layers of sand and mud have built up. 
  The skeleton is slowly turning into rock.
  Over the years, layers  
  of mud settle on top  
  and bury the animal.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  18
  PREHISTORIC LIFE
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  19
  PREHISTORIC LIFE
  DINOSAUR NATIONAL MONUMENT
  In the United States, Dinosaur National Monument, on  
  the border between Utah and Colorado, has been the site  
  of huge numbers of fossilized dinosaur ﬁnds. An exposed 
  wall of sandstone is on display there; it contains around 
  1,500 fossilized dinosaur bones dating back to between  
  155 and 148 million years ago.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  20
  A fossil hunter’s toolbox
  Scientists who study fossils are called 
  paleontologists. Paleontologists use basic 
  digging tools to remove fossils from the 
  ground, such as hammers, chisels, and 
  trowels. Brushes help sweep away dust.
  PREHISTORIC LIFE
  Fossil hunting
  You may have seen a fossil hunt on television, 
  or you may have visited a fossil site. Perhaps 
  you have been lucky enough to ﬁnd your own 
  fossil. What happens on an organized fossil dig?
  IT WAS FOUND THERE!
  Every dinosaur dig is diﬀerent. Some fossils are found embedded 
  in solid rock that needs to be chipped away bit by bit. Others fall 
  out of soft, crumbly cliﬀs and can be very fragile, falling apart 
  easily. The Ouranosaurus (a plant-eating dinosaur) above was 
  found buried in the desert sand and was easy to dig out by hand.
  UNCOVERING FOSSILS
  ■  Articulated skeleton. This is a 
  skeleton that is still joined together.  
  It may be complete, but pieces are  
  usually missing.
  ■  Associated skeleton. This means the 
  bones have broken up and spread out, 
  but they can be identified as belonging 
  to the same dinosaur.
  ■  Isolated bone. This is a bone that has 
  been separated from its skeleton, and 
  fossilized alone. It may be a leg bone 
  such as a femur (thigh bone), which is a 
  large fossil.
  ■  Float. These are scraps of fossilized 
  bone—the fossil has shattered, and the 
  scraps are usually too small to be useful.
  Paleontologists classify the dinosaur fossils they uncover in one of four ways.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  21
  PREHISTORIC LIFE
  EXCAVATING A DINOSAUR
  The excavation of two dinosaur fossils, Afrovenator 
  (a theropod) and Jobaria (a sauropod) in Africa is 
  shown here in a series of photographs. The bones were 
  ﬁrst discovered by local tribesmen, who found them 
  jutting out of desert rock. It can take many months  
  to excavate a complete dinosaur ﬁnd, and this dig  
  was no exception.
  u A SLOW JOB Once the paleontologists have carefully 
  removed all dirt from around each of the fossilized bones, 
  the position of each bone is carefully mapped on graph 
  paper, with the help of a square grid called a quadrat.
  , ON SHOW 
  As more soil is removed, 
  the fossils become clear. 
  The team was dealing 
  with a theropod that 
  could reach 30 ft (9 m) 
  and a sauropod that 
  could reach 60 ft (18 m) 
  in length, so the bones 
  were large.
  , MAKING A START 
  Painstaking work over  
  a number of weeks to 
  remove rock ﬁnally 
  revealed each fossil.  
  A large team of people 
  worked on this dig.
  , SITE MAP 
  One paleontologist made 
  a ﬁnal, detailed drawing 
  of the bones in position. 
  This showed clearly how 
  some bones had separated 
  from the animal over the 
  millions of years it had 
  lain encased in rock.
  , WRAP IT UP!
  Once the bones were 
  ready to be removed,  
  they were covered with 
  bandages soaked in a 
  plaster solution. When 
  the plaster sets hard, this 
  protects the fossil, ready 
  for its removal to a 
  museum laboratory for 
  further study. 
  So many bones
  One quarry has yielded far more dinosaur 
  bones than any other. From 1909 to 
  1924, 385 tons (350 metric tons) of 
  dinosaur fossils were removed from 
  the Dinosaur National Monument 
  on the Utah-Colorado border. 
  That’s a lot of bones!
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  22
  A look at size
  From dinosaurs the size of chickens to lumbering sauropods, the 
  animals that have walked and swum on Earth have varied enormously 
  in size and shape and length. Let’s take a look at a few examples. 
  PREHISTORIC LIFE
  Orca
   
  ■ Length 30 ft (9 m) 
  Sperm whale
   
  ■ Length 66 ft (20 m) 
  Mammoth
   
  ■ Shoulder height 
  16 ft (5 m) 
  Tyrannosaurus
   
  ■ Length 39 ft (12 m) 
  Great white shark
   
  ■ Length 20–26 ft (6–8 m)
  Hatzegopteryx
   
  ■ Wingspan 36 ft 
  (11 m)
  Brachiosaurus
   
  ■ Length 75 ft (23 m) 
  Shonisaurus
   
  ■ Length 66 ft (20 m) 
  Predator X
   
  ■ Length 49 ft 
  (15 m) 
  Leedsichthys
   
  ■ Length 30 ft (9 m) 
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  23
   
  ■ Biggest killer on land The dinosaur 
  Spinosaurus is the largest known land-dwelling 
  meat eater. It was 50 ft (16 m) long and  
  weighed 13½ tons (12 metric tons).
  FACT FILE
   
  ■ Smallest dinosaur  
  Pigeon-sized Anchiornis 
  is the smallest known 
  prehistoric dinosaur. The 
  Cuban bee hummingbird is 
  the smallest living dinosaur.
   
  ■ Largest flying animal  Hatzegopteryx 
  was a pterosaur—a kind of flying reptile.  
  Its wingspan was about 36 ft (11 m), 
  making it as big as a small aeroplane.  
  For comparison, the bird with the largest 
  wingspan today is the wandering albatross, 
  with a span of 12 ft (3.6 m).
   
  ■ Largest  The blue whale is the world’s 
  largest living animal. 
  Its heart alone is 
  the size of 
  a small 
  car.
  The sizes shown in the picture to the left are 
  the maximum these animals are known to 
  have reached. The artwork is not perfectly 
  to scale, but it gives an idea of what these 
  animals may have looked like if they could 
  have been brought together.
  Largest land animal?
  The largest animal ever to walk on Earth might have been a 
  dinosaur called Amphicoelias (am-fee-SEE-lee-ass). More than 
  a century ago, a single backbone of Amphicoelias was found. 
  It was drawn and described, but then mysteriously disappeared.  
  The description suggests Amphicoelias was an incredible 130–196 ft 
  (40–60 meters) in length and 135 tons (120 metric tons) in weight.
  PREHISTORIC LIFE
  Amphicoelias fragillimus
  Argentinosaurus huinculensis
  Sauroposeidon proteles 
  Supersaurus vivianae
  Diplodocus hallorum
  Blue whale
   
  ■ Length 100 ft (30 m)
  Livyatan  
  (Prehistoric toothed whale)
   
  ■ Length (estimated) Up to 57 ft (17 m)
  Megatooth shark
   
  ■ Length 66 ft (20 m) 
  Human
   
  ■ Tallest man ever 8 ft 11 in (12.7 m)
  Triceratops
   
  ■ Length 30 ft (9 m)
  African elephant
   
  ■ Shoulder height 
  13 ft (4 m) 
  Temnodontosaurus
   
  ■ Length 39 ft (12 m)
  Mosasaurus
   
  ■ Length 49 ft (15 m) 
  Albatross
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  24
  INVERTEBRATES
  u TRILOBITES Soft-bodied invertebrates 
  don’t usually fossilize, but those with hard 
  shells, such as these trilobites, have left 
  impressive fossil records. Some trilobite fossils 
  date back more than 500 million years.
  INVERTEBRATES
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  25
  Invertebrates are animals 
  that have neither a 
  backbone nor a bony 
  internal skeleton. This is 
  an incredibly varied group; 
  it includes insects, spiders, 
  mollusks, sponges, 
  jellyﬁsh, and worms.
  INVERTEBRATES
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  26
  INVERTEBRATES
  What are invertebrates?
  From insects to mollusks, and from worms to jellyﬁsh, invertebrates dominate our 
  planet in terms of their numbers: they make up around 97 percent of the animal 
  kingdom. What features do these animals share in common? Very few! However, 
  they are animals that possess neither a backbone, nor a bony internal skeleton.
  Invertebrates are divided into about 30 groups. They include:
  . TIGER LEECH Some 
  leeches, like this one, will wait 
  for a passing animal and feed 
  oﬀ that animal, sucking  
  its blood.
  . GIANT AFRICAN 
  SNAIL These are large 
  snails—they can reach 
  8 in (20 cm)  
  in length.
  The group Arthropoda includes 
  insects, arachnids (creatures 
  such as spiders and 
  scorpions), and 
  crustaceans. 
  Arthropods  
  make up the 
  largest group of 
  invertebrates, and account for about  
  90 percent of known animal species.
  ARTHROPODA
  MOLLUSCA
  ANNELIDA
  , GARDEN CENTIPEDE 
  A centipede has at least 15 
  pairs of legs. Centipedes are 
  carnivorous, hunting prey 
  such as insects and spiders.
  d ROSE CHAFER BEETLE There are 
  more than 300,000 species of beetle, some 
  very brightly colored.
   Imperial scorpion 
  Annelid worms have bodies 
  that are divided into segments. 
  Earthworms and bristleworms 
  are types of annelid worm. 
  Members of this group can be 
  found living in seawater, in fresh 
  water, and on land. Amazingly, there 
  are more than 12,000 recognized 
  species of annelid worm.
  From a small garden snail to a giant 
  squid, the group that forms Molluska 
  is incredibly varied. Most mollusks 
  have a shell, or at least the remnants 
  of one, but not all—octopuses 
  have no shell, and neither  
  do slugs.
  u NUDIBRANCH These 
  marine mollusks are often 
  called “sea slugs.” The infant 
  form (larva) has a shell.
  u RAGWORM These creatures have a 
  pair of swimming legs (called parapods) 
  on each segment of their bodies.
  Squid
  Earthworm
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  27
  INVERTEBRATES
  d ELEPHANT EAR 
  SPONGE Some 
  sponge species can 
  grow quite large. 
  This one has 
  reached 3 ft (1 m)  
  in height and  
  is still growing.
  d  CROWNOFTHORNS SEA STAR This 
  is the largest starﬁsh and a voracious predator, 
  feeding on corals. It has needle-sharp spines, each 
  capable of injecting a nasty venom.
  d SEA NETTLES Jellyﬁsh, such as these sea 
  nettles, have bodies that are largely made of 
  water. Take a jellyﬁsh out of water, and the 
  shape will collapse.
  CNIDARIA
  ECHINODERMATA
  PORIFERA
  TAKE A LOOK—METAMORPHOSIS
  Most invertebrates leave the egg as a larva and undergo 
  several developmental stages before reaching adult 
  form. This is known as metamorphosis.
  , CATERPILLAR 
  After hatching from 
  an egg, a butterﬂy 
  caterpillar proceeds 
  to eat and eat and 
  eat. Its job is to  
  grow quickly.
  . TIME TO 
  PUPATE 
  A tough, leathery 
  coat forms around 
  the caterpillar, and it 
  becomes a pupa. After some time,  
  a butterﬂy will break free.
  d ADULT FORM Finally, the butterﬂy 
  emerges. It has to spread out its wings to  
  dry before it can ﬂy.  
  A butterﬂy is the 
  adult form.
  This group includes 
  sea jellies (also 
  known as 
  jellyﬁsh), corals, 
  and sea anemones. 
  They have stinging 
  cells called 
  nematocysts. Some can 
  swim, while others remain ﬁxed to the 
  seabed, waiting for food to drift past.
  Porifera are also called sponges. They 
  were mistaken for plants until the 1700s 
  but, in fact, are very simple animals, with 
  no arms, legs, heads, or sense organs. 
  Sponges have simple baglike or tubelike 
  bodies and live stuck to the seaﬂoor, 
  ﬁltering food from 
  the water.
  Many echinoderms have very spiny bodies 
  and nearly all live on the seaﬂoor—none 
  can survive in fresh water. They include 
  starﬁsh (sea stars), sea 
  urchins, and sea 
  cucumbers. Most of 
  these animals can 
  move around, 
  and they have up 
  to 20 legs—but 
  no brain.
  . BRAIN 
  CORAL Many 
  corals are named 
  for their 
  appearance, like 
  this heavily 
  wrinkled coral.
  . SEA CUCUMBER 
  These echinoderms are 
  found on seabeds all 
  over the world.
  , AZURE VASE 
  SPONGE There 
  are thousands of 
  sea sponges, some 
  very colorful.
  Sea anemone
  Sunﬂower sea star
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  28
  The first animals
  Fossils tell us that animal life began about 600 million years ago. The 
  first animals lived in darkness, rooted to the seabed, and had simple, 
  soft bodies shaped like disks or leaves, with which they gathered 
  nutritious chemicals or particles in the water. These strange beings 
  seem to have had no legs, no heads, no mouths, 
  no sense organs, and no internal organs.
  INVERTEBRATES
  Living stromatolites 
  in Australia
  FIRST LIFE
  For nearly nine-tenths of the Earth’s history, 
  there were no animals or plants. During most  
  of this early era, called the Precambrian period, 
  the only life forms were microscopic single cells. 
  Some grew in colonies on the sea ﬂoor, building 
  up over time to form cushion-shaped mounds of 
  rock – “stromatolites” – that still form today.  
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  29
  INVERTEBRATES
   
  ■ When  558–555 million years ago (Precambrian) 
   
  ■ Fossil location Australia, Russia 
   
  ■ Habitat  Seaﬂoor 
   
  ■ Length  3⁄8–1 in (1–2.5 cm) 
  Parvancorina had a shield-shaped front end that 
  may have been a head and that faced into the 
  current when it 
  was alive. It also 
  had a central 
  ridge flanked by 
  what look like 
  segments. Many 
  fossils have a 
  well-preserved 
  shape, suggesting 
  that its body had 
  a hardened  
  outer casing.
  Parvancorina
  PAR-van-coe-REE-na
   
  ■ When  550 million years ago (Late Precambrian) 
   
  ■ Fossil location  Australia, Russia 
   
  ■ Habitat  Seaﬂoor 
   
  ■ Length  1¼ in (3 cm) 
  Spriggina may have been one of the very first 
  animals with a front and back end. It may even 
  have had a head with eyes and mouth, suggesting 
  it was one of the first predators to exist. Some 
  scientists think it may have been an early 
  trilobite. Others liken it to worms. 
  Spriggina
  sprig-EEN-a
   
  ■ When  670 million years ago (Precambrian) 
   
  ■ Fossil location Australia, Russia, China, Mexico, 
  Canada, British Isles, Norway 
   
  ■ Habitat  Seaﬂoor 
   
  ■ Length  1–12 in (2.5–30 cm) across 
  Mysterious Cyclomedusa was originally mistaken 
  for a jellyfish because of its circular shape, but 
  neighboring fossils are often misshapen, as 
  though growing around each other on the 
  seafloor. Some 
  scientists think 
  Cyclomedusa 
  was just a 
  colony of 
  microbes or 
  the anchor for 
  the stalk of a 
  bigger creature.
  Cyclomedusa
  cy-clo-med-OO-sa
   
  ■ When  560–555 million years ago (Precambrian) 
   
  ■ Fossil location Australia, Russia 
   
  ■ Habitat  Seaﬂoor 
   
  ■ Length  3⁄8–39 in (1–100 cm) 
  One of most baffling Ediacaran fossils is 
  Dickinsonia—a flat, round organism that 
  appears to have had distinct front and back 
  ends but no head, mouth, or gut. Studies 
  suggest Dickinsonia lived fixed to the seafloor, 
  perhaps absorbing food through its base.
  Dickinsonia
  dickin-SO-nee-a
   
  ■ When  575–545 million years ago (Precambrian) 
   
  ■ Fossil location  England, Australia, Canada, Russia 
   
  ■ Habitat  Seaﬂoor 
   
  ■ Length  6 in–6½ ft (0.15–2 m) 
  Discovered by a schoolboy in 1957, Charnia 
  caused a sensation because it came from rocks 
  thought far too old to contain animal fossils. 
  It had a feather-shaped body and lived rooted 
  to the seafloor by a stem, perhaps feeding  
  on microbes filtered out of the water. Its  
  main body was made of rows of branches  
  that gave it a striped, quilted appearance. 
  Some experts think its body might  
  have housed algae that made it green 
  and allowed it to gather energy  
  from sunlight (photosynthesis).
  Charnia
  CHAR-nee-a
  u DICKINSONIA fossils are usually oval, 
  with what look like segments extending from  
  a central groove. Hundreds of fossils have been 
  found, with a huge variety of sizes.
  u SEGMENTS
  Fossils show that Spriggina’s body was made 
  of segments. Most fossils are curved in different 
  ways, suggesting it had a flexible body.
  , ANCHOR
  Some fossil of  Charnia have a stem with a 
  disk at the base. These disks, buried in the  
  sandy seabed, may have been anchors that  
  held Charnia fixed in place while the 
  feathery top waved about in the current. 
  DID YOU KNOW...?
  In 1946, a scientist named Reg Sprigg was 
  eating a packed lunch in the Ediacara Hills  
  of Australia when he spotted what looked like 
  jellyﬁsh fossils in the rocks. He’d discovered 
  something amazing: the oldest animal fossils 
  in the world. One was named Spriggina, after 
  him, and all the fossils 
  from the period  
  are now called 
  Ediacaran fossils.
  Charnia
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  30
  Cambrian explosion
  About 530 million years ago, a huge range of new 
  animals appeared in the seas, including the ﬁrst 
  creatures with clear legs, heads, sense organs, skeletons, 
  and shells. All the main categories of invertebrates 
  (animals without backbones) known today seem to  
  have evolved almost at once, as well as some weird 
  creatures quite unlike anything else. Scientists call this 
  mysterious burst of life the Cambrian explosion.
  INVERTEBRATES
   
  ■ When  505 million years ago (Middle Cambrian) 
   
  ■ Fossil location  Canada 
   
  ■ Habitat  Seaﬂoor 
   
  ■ Length  1–2 in (3–5 cm) 
  Wiwaxia looked like a tiny, armored 
  porcupine, since its body was covered with 
  protective spines and rows of overlapping 
  armor plates. Its ﬂat lower surface, where  
  the mouth was located, did not have any 
  protection. The mouth had two or three rows 
  of sharp, conical teeth that may have been used 
  to scrape algae from the seabed. Wiwaxia had 
  no distinct head or tail and was probably blind, 
  relying on touch and smell to ﬁnd the way. 
  Wiwaxia
  we-WAX-ee-a
  u FOSSILS of Anomalocaris 
  often show only a small part  
  of the body. This is one of  
  its feeding claws.
   
  ■ When  505 million years ago (Middle Cambrian) 
   
  ■ Fossil location  Canada, S. China 
   
  ■ Habitat  Oceans 
   
  ■ Length  Up to 3 ft (1 m) 
  A little like a giant shrimp, Anomalocaris 
  (below) was the largest animal found in the 
  Burgess Shale fossil bed of Canada (see box). 
  Experts suspect it was the top predator in 
  Cambrian seas and used a pair of spiked claws 
  attached to its head to grasp prey such as 
  trilobites. It had no legs but could swim by 
  ﬂexing its segmented body and waving the ﬂaps 
  on its sides. Large compound eyes indicate it 
  had good vision and hunted by sight.
  Anomalocaris
  a-NOM-a-low-CAR-iss
  u THIS WIWAXIA fossil 
  from the Burgess Shale fossil 
  bed in Canada is about 
  500 million years old. The 
  armorlike plates on its back 
  are called sclerites.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  31
  INVERTEBRATES
   
  ■ When  505 million years ago (Middle Cambrian) 
   
  ■ Fossil location  Canada, China 
   
  ■ Habitat  Oceans 
   
  ■ Length  Up to 1 in (2.5 cm)  
  Hallucigenia is one of the 
  strangest animals from the 
  Cambrian Period. At one end  
  is a large blob that may be a  
  head, but with no mouth or eyes.  
  It may simply be a stain on the fossil 
  and not a part of the animal. Running 
  along the wormlike body were rows  
  of sharp spines and rows of fleshy 
  tentacles. Orginally the spines 
  were thought to be legs, but 
  scientists now think the 
  fleshy tentacles were the 
  legs, despite not being 
  arranged in pairs.
  Hallucigenia
  ha-lucy-JEAN-ee-a
   
  ■ When  505 million years ago (Middle Cambrian) to now 
   
  ■ Fossil location Canada 
   
  ■ Habitat  Oceans 
   
  ■ Length  1½–3¼ in (4–8 cm) 
  Ottoia was a kind of worm that lived in 
  U-shaped burrows, which is why its fossils  
  are usually curved. Its mouth was covered  
  with tiny hooks and could be turned inside 
  out like a sock to capture small animals  
  from the muddy seafloor. Fossilized food 
  remains inside Ottoia’s gut reveal that it was 
  a cannibal, preying on its own kind as well 
  as devouring small shelled animals. Ottoia 
  is one of the most common early Cambrian 
  fossils, with around 1,500 known specimens.
   
  ■ When  505 million years ago (Middle Cambrian) 
   
  ■ Fossil location  Canada 
   
  ■ Habitat  Oceans 
   
  ■ Length  1 in (3 cm) wide, below the tentacles 
  Echmatocrinus lived attached to the seafloor, 
  its cone-shaped body topped by a ring of 7–9 
  tentacles, each bearing small side-branches.  
  The surface of the main cone was covered with  
  a jigsaw of hard, protective plates. When it was 
  first discovered, scientists thought Echmatocrinus  
  might be related to starfish, but it lacks the 
  five-sided symmetry of the starfish family. Some 
  experts think it might instead be a kind of coral.
  Echmatocrinus
  ECK-mat-oh-crine-us
  Ottoia
  ot-OY-ah
  Ottoia fossil
  DID YOU KNOW...?
  All the fossils on these two pages come from 
  the Burgess Shale Formation in the Rocky 
  Mountains in Canada. Littering the ground at 
  this famous mountaintop site are hundreds  
  of beautifully preserved animal fossils dating 
  back almost to the very dawn of animal life. 
  The Burgess Shale contains imprints of soft 
  body parts that normally don’t fossilize and 
  reveals that invertebrate life was already 
  amazingly varied half a billion years ago.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  32
  Opabinia
  One of the weirdest prehistoric animals ever 
  discovered, Opabinia had five eyes on stalks and 
  a long, flexible trunk (proboscis) tipped with a 
  grasping claw. This mouse-sized sea creature 
  probably used its trunk in the same way an 
  elephant does, picking up items of food with  
  the tip and then passing them to its mouth.
  INVERTEBRATES
  u FOSSILS of Opabinia were discovered in a famous fossil 
  bed in Canada called the Burgess Shale. The Burgess Shale 
  contains surprisingly clear impressions of soft body parts that 
  were buried in mud on the seafloor half a billion years ago 
  during the Cambrian Period. There are so many weird and 
  wonderful animal species in the Burgess Shale that their sudden 
  appearance is known as the “Cambrian Explosion.”
  Claw
  Flexible trunk 
  (proboscis)
  Head
  Eye
  Eye
  Precambrian Eon
  Cambrian
  Ordovician
  Silurian
  Devonian
  416
  444
  488
  542 million years ago
  4.6 billion years ago
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  33
  INVERTEBRATES
  OVERLAPPING FLAPS ran 
  along each side of Opabinia’s 
  body. Perhaps the animal swam 
  by moving the flaps up and down 
  in a wave pattern to push itself 
  through the water.
   
  ■ When  515–500 million years ago 
  (Middle Cambrian) 
   
  ■ Fossil location  Canada
   
  ■ Habitat  Near the seabed
   
  ■ Length  2½ in (6.5 cm)
  Opabinia’s body consisted of 16 segments, 
  each of which had side flaps and gills on the 
  underside for breathing in water. Scientists 
  think the animal lived near the seabed and 
  used its trunk to fish around in the mud for 
  food. It had no jaws or teeth, so it probably 
  only ate soft items of food. Although very 
  different from all other living or prehistoric 
  animals, Opabinia is thought to be related 
  to the arthropods (invertebrates with jointed 
  limbs and external skeletons, such as insects, 
  spiders, and crabs).
  Opabinia
  OH-pa-BIN-ee-a
  Segments
  Mouth (underneath)
  Tail
  Carboniferous
  Permian
  Triassic
  Jurassic
  Cretaceous
  Paleogene
  Neogene
  251
  299
  359
  200
  145
  65
  23
  Now
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  34
  Marrella
  Some 500 million years ago, the tiny, shrimplike 
  creature Marrella darted around the seafloor, 
  beating its 50 feathery legs as it swam in 
  search of dead animals to eat. Marrella 
  appeared in the “Cambrian Explosion,” 
  when a vast range of animal life evolved 
  in a short space of time.
  INVERTEBRATES
   
  ■ When  515–500 million years ago 
  (Middle Cambrian) 
   
  ■ Fossil location  Canada 
   
  ■ Habitat  Seabed 
   
  ■ Length  ¾ in (2 cm)  
  Marrella’s head was protected by a 
  large and possibly colorful shield with 
  four long, backward-pointing spikes. 
  Under the shield was Marrella’s 
  flexible body, which consisted of 25 
  segments, each with a pair of feathery 
  legs that doubled as gills for breathing 
  underwater. Attached to the head were 
  two pairs of long, flexible antennae 
  (feelers). Marrella was one of the first 
  arthropods—the group that today 
  includes insects, spiders, and other 
  animals with external skeletons.
  Marrella
  ma-RELL-a
  SEABED SEARCHER . 
  Marrella probably swam along the seabed 
  or just above it, using its long antennae to 
  sweep the mud in search of food.
  Precambrian Eon
  Cambrian
  Ordovician
  Silurian
  Devonian
  Carboniferous
  Permian
  251
  299
  359
  416
  444
  488
  542 million years ago
  4.6 billion years ago
  Shield
  Antennae 
  ( feelers)
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  35
  INVERTEBRATES
  u PRESERVED IN MUD
  More than 15,000 fossils of Marrella 
  have been found, all of them at one 
  location in Canada. The fossils are  
  in a type of rock called shale, formed  
  from seafloor mud.
  , CHANGING COLORS
  Studies of Marrella fossils suggest that 
  its surface was iridescent, meaning  
  that it had a colorful sheen that 
  glinted and changed color as the  
  light moved, like the surface of a  
  soap bubble or a butterfly’s wings.
  Triassic
  Jurassic
  Cretaceous
  Paleogene
  Neogene
  200
  145
  65
  23
  Now
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  36
  Trilobites
  For more than 250 million years, the ancient seas  
  teemed with trilobites—prehistoric animals related to 
  today’s insects, woodlice, and crabs. There were more  
  than 17,000 diﬀerent types of trilobite, ranging from 
  the ﬂea-sized to monsters twice the size of this book. 
  Most crawled along the ocean ﬂoor in search of food, 
  but a few were swimmers or ﬂoaters that drifted 
  through the water.
  FAMILY FACT FILE
  Key features
   
  ■ Head shield
   
  ■ Segmented, three-lobed body
   
  ■ Many had compound eyes
   
  ■ External skeleton (exoskeleton)
  When
  Trilobites appeared in the Cambrian 
  Period, 526 million years ago, and 
  disappeared at the end of the Permian 
  Period, 250 million years ago, when 
  the last species was wiped out. 
   
  ■ When  300–251 million years ago 
  (Late Carboniferous to Late Permian) 
   
  ■ Fossil location  N. America, Europe, Asia, 
  W. Australia 
   
  ■ Habitat  Seaﬂoor 
   
  ■ Length  1–1¼ in (2.5–3 cm)  
  Ditomopyge lived toward the end of the trilobites’ 
  reign, just before the age of the dinosaurs. It 
  had a hard outer skeleton (exoskeleton) made 
  up of overlapping plates covering its body 
  segments. Underneath, each segment had a pair 
  of wriggling legs. The head was protected by  
  a large shield with backward-pointing spines and 
  would have sported a pair of ﬂexible antennae 
  (feelers) for ﬁnding the way and tasting food.
  Ditomopyge
  DIT-o-mo-PY-gee
  INVERTEBRATES
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  37
   
  ■ When  465 million years ago (Middle Ordovician) 
   
  ■ Fossil location  France, Portugal, Spain
   
  ■ Habitat  Seaﬂoor 
   
  ■ Length  Up to 1½ in (4 cm) 
  Like many trilobites, Eodalmanitina had 
  large eyes and good vision. Trilobites 
  were among the first animals to evolve 
  sophisticated eyes. These consisted of 
  many tiny, crystalline lenses packed 
  together in a honeycomb pattern,  
  like the compound eyes of insects. 
  Eodalmanitina had distinctive bean-
  shaped eyes. Its long body tapered toward 
  the tail, which was tipped by a short spine.
  Eodalmanitina
  EE-o-dal-man-ee-tee-na
   
  ■ When  380–359 million years ago 
  (Middle to Late Devonian) 
   
  ■ Fossil location  Morocco 
   
  ■ Habitat  Seaﬂoor 
   
  ■ Length  2½ in (6.6 cm) 
  Ceratarges was one of many 
  trilobites with spectacular spines 
  and horns. These prickly weapons 
  may have been used to ward off 
  predators. Another theory, however, 
  is that they evolved as a result of 
  battles between rival trilobites 
  fighting over mates, like the 
  antlers of modern stag beetles.
  Ceratarges
  SER-a-tar-gees
   
  ■ When  444 million years ago (Silurian) 
   
  ■ Fossil location  Worldwide 
   
  ■ Habitat  Seaﬂoor 
   
  ■ Length  Up to 2 in (5 cm) 
  This small trilobite had 
  many berry-shaped bumps 
  on the shield protecting  
  its head. Encrinurus’s eyes 
  were probably situated at 
  the end of short stalks. It 
  may have spent a lot of 
  time hiding in the mud on 
  the seabed, with only its  
  eyes above the surface.
  Encrinurus
  EN-crine-yoo-rus
  . ROLLING UP
  Phacops could curl 
  up in a tight ball to 
  protect its softer undersides 
  when attacked, much like 
  some modern woodlice. 
   
  ■ When  380–359 million years ago 
  (Middle to Late Devonian) 
   
  ■ Fossil location  Worldwide 
   
  ■ Habitat  Seaﬂoor
   
  ■ Length  Up to 2¼ in (6 cm) 
  Named for its keen sense of  
  sight, Phacops (“lens eye”), like 
  Eodalmanitina, had bulging 
  eyes that gave it good vision, 
  suggesting it lived in well-lit areas 
  such as shallow seas. One of the 
  most common and widespread 
  trilobites, Phacops has been found 
  in Europe, Africa, Australia, and 
  North America. Geologists even 
  use its fossils as a handy way to 
  estimate the age of a rock.
  Phacops
  FAY-cops
  Spine
  Eye
  Lenses in eye
  INVERTEBRATES
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  38
  Selenopeltis
  The common trilobite Selenopeltis 
  lived in cool waters along the coast  
  of Gondwana, a mighty prehistoric 
  continent that later broke apart  
  to form South America, Africa, 
  and Australia. It had long, 
  sweeping spines that give its 
  fossils a graceful appearance, 
  making them a favorite 
  among fossil collectors. 
   
  ■ When  471–445 million years ago (Early to Late Ordovician) 
   
  ■ Fossil location  British Isles, France, Iberia, Morocco, 
  Czech Republic, Turkey 
   
  ■ Habitat  Ocean waters 
   
  ■ Length  Up to 4½ in (12 cm) 
  Selenopeltis had a wide skeleton and a 
  distinctive squarish head. Spines extended 
  backward from its cheeks and the sides of  
  each body segment. Unlike most other 
  trilobites, it had small eyes. 
  Selenopeltis
  se-LEE-no-pel-tiss
  INVERTEBRATES
  Precambrian Eon
  Cambrian
  Ordovician
  Silurian
  Devonian
  416
  444
  488
  542 million years ago
  4.6 billion years ago
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  39
  , SPINY TRILOBITES 
  This amazing slab of rock 
  contains more than just 
  Selenopeltis fossils. There are 
  two other types of trilobite (a 
  large one without spines and 
  a small one with a tail spine) 
  and lots of starfish—see if  
  you can find them all.
  INVERTEBRATES
  Carboniferous
  Permian
  Triassic
  Jurassic
  Cretaceous
  Paleogene
  Neogene
  251
  299
  359
  200
  145
  65
  23
  Now
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  40
  Echinoderms
  The starfish and sea urchins we see at  
  the beach belong to an ancient group of 
  sea-dwelling animals known as echinoderms 
  (“ee-KYE-no derms”). Echinoderms have 
  round or star-shaped bodies and feet  
  like tiny suckers, but no heads 
  or brains. Fossils reveal that 
  echinoderms of the distant 
  past were much like those  
  we see today.
  INVERTEBRATES
   
  ■ When  235–215 million years ago (Middle Triassic) 
   
  ■ Fossil location Europe
   
  ■ Habitat  Shallow seas 
   
  ■ Size  Cup 1½–2¼ in (4–6 cm) long 
  Attached to the seafloor by a stalk, Encrinus 
  used a ring of 10 feathery arms to catch tiny 
  organisms floating past. The organisms, trapped 
  in a sticky fluid, were then swept by tiny hairs 
  toward a central mouth. Encrinus belonged 
  to a class of echinoderms known as crinoids  
  or sea lilies that still exists today. 
  Encrinus
  EN-crine-us
  Pentasteria
  PEN-ta-STEER-ee-a
   
  ■ When  203–100 million years ago 
  (Early Jurassic to Early Cretaceous) 
   
  ■ Fossil location  Europe 
   
  ■ Habitat  Sand beds 
   
  ■ Size  Up to 
  4½ in (12 cm) across 
  Pentasteria was 
  a starfish that 
  lived during  
  the age of the 
  dinosaurs. It  
  was much like a 
  modern starfish, with 
  five arms, a mouth in  
  the middle of its underside, 
  and two rows of tubelike feet along each arm. 
  Unlike modern starfish, however, it couldn’t  
  use its feet as suckers to prize open shells. 
  Clypeus
  CLY-pee-us
   
  ■ When  176–135 million years ago 
  (Middle to Late Jurassic) 
   
  ■ Fossil location  Europe, Africa 
   
  ■ Habitat  Burrows on the seaﬂoor 
   
  ■ Size  2–4½ in (5–12 cm) across  
  Clypeus was a type of sea urchin. Like a modern 
  sea urchin, it had a hard, rounded shell made up 
  of five parts arranged in a star pattern. The shell 
  was covered by spines, but unlike 
  the stiff, pointed spines of 
  many sea urchins, these 
  were soft and hairlike. 
  Clypeus found food 
  by burrowing  
  and eating its way 
  through the mud  
  on the seafloor.
  Spine bases
  Encrinus fossil
  Encrinus trapped food with its sticky 
  arms. The arms could close tightly for 
  protection from predators.
  FAMILY FACT FILE
  Key features
   
  ■ Body divided into five equal parts 
  arranged in a circle around a central disk
   
  ■ Rows of small, suckerlike feet on base
   
  ■ No front or back and no head or brain
  When
  Echinoderms first appeared at the  
  start of the Cambrian Period, about  
  530 million years ago. Over 7,000 
  species are found in oceans across  
  the world today.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  INVERTEBRATES
  Pentacrinites
  PEN-ta-CRINE-ee-tees
   
  ■ When  208–135 million years ago (Jurassic) 
   
  ■ Fossil location  Europe 
   
  ■ Habitat  Open seas 
   
  ■ Size  Arms up to 31 in (80 cm) long  
  Pentacrinites was a crinoid (sea lily) 
  as tall as a man and lived rooted  
  to one spot by a stalk, catching food  
  in its feathery arms. Its hundreds of 
  densely packed arms made it look more 
  like a beautiful plant than an animal.  
  Its fossils are often found with fossilized 
  wood, suggesting that the creature may 
  sometimes have attached itself to 
  floating driftwood.
  ��
  �When  176–65 million years ago 
  (Middle Jurassic to Late Cretaceous) 
  ��
  �Fossil location  England 
  ��
  �Habitat  Rocky seabeds 
  ��
  �Size  Including spines 8 in (20 cm) diameter
  Without spines ¾–1½ in (2–4 cm)
  Fossils of Hemicidaris are covered with 
  bumps where its vicious, 3 in (8 cm) long 
  spines were attached. These were flexible, 
  allowing Hemicidaris 
  to move its spines 
  with muscles.  
  It lived on firm 
  seabeds and used 
  its sticky feet to 
  creep around.
  Hemicidaris
  HEM-ee-sid-AR-is
  Attachment point for spine
  Sea urchins are small, ball-shaped creatures 
  that often have prickly, even poisonous spines 
  for protection. They creep slowly across the 
  seaﬂoor using dozens of tiny sticky feet.
  LIVING RELATIVE
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  42
  Brittle stars
  Look at any part of the seabed and you are likely to find star-shaped 
  creatures with long, slender arms wriggling across the bottom. 
  These are not fish, but invertebrates called brittle stars, and they are 
  relatives of starfish and sea urchins. They are also known as snake 
  stars because of the way they move their arms. Palaeocoma was an 
  early kind of brittle star. Wary of predators, Palaeocoma, like 
  modern brittle stars, may have hidden in 
  cracks in rocks and corals, coming out 
  only at night to feed.   
   
  ■ When  Nearly 200 million years ago (Early Jurassic)
   
  ■ Fossil location  Europe
   
  ■ Habitat  Seaﬂoor
   
  ■ Size  2–4 in (5–10 cm) across
   
  ■ Diet  Remains of plants and animals 
  Palaeocoma had a flat, central disklike body. 
  Extending from it were five long, spiny arms, 
  with which it moved swiftly along the seabed. 
  When disturbed, it could escape quickly, pulling 
  and pushing its body using the muscles in  
  its arms. On the underside of its body was a 
  star-shaped mouth containing five toothed jaws. 
  When feeding, it used the tiny, muscular tube 
  feet underneath its arms to sweep food into its 
  mouth. It had no eyes, but may have been able 
  to sense light through its feet.
  Palaeocoma
  pale-ee-oh-COAM-ah
  INVERTEBRATES
  542 million years ago
  4.6 billion years ago
  Precambrian Eon
  Cambrian
  Ordovician
  Silurian
  Devonian
  Carboniferous
  299
  359
  416
  444
  488
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  43
  Around 2,000 species of brittle star exist today, in icy seas  
  and warm waters all over the world. These, often brilliantly 
  colored, creatures—some with patterned bodies—have ﬁve 
  snakelike arms. When attacked, they shed an arm, which 
  wriggles for a while, confusing the predator. Brittle stars  
  quickly regrow the lost arm.
  LIVING RELATIVE
  Drifting with the tide 
  Like many sea creatures, brittle stars live on the 
  seafloor as adults but spend the early part of their 
  lives as plankton—tiny organisms that float freely in 
  the sunlit upper waters of the ocean. They drift with  
  the currents for weeks, traveling hundreds of miles 
  before finally sinking to the seafloor, where they 
  change into adult brittle stars. 
  INVERTEBRATES
  Permian
  Triassic
  Jurassic
  Cretaceous
  Paleogene
  Neogene
  251
  200
  145
  65
  23
  Now
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  44
  INVERTEBRATES
  Spiders and scorpions
  Spiders and scorpions belong to an ancient  
  family of predatory animals called chelicerates 
  (“kell-ISS-er-ates”), all of which have special 
  mouthparts that they use either as pincers  
  or fangs. Modern chelicerates are small,  
  but their earliest 
  ancestors grew to 
  gigantic sizes and 
  were among the  
  top predators of their  
  time. The biggest of these 
  prehistoric monsters were  
  the sea scorpions.
   
  ■ When  400–380 million years ago 
  (Late Silurian to Middle Devonian) 
   
  ■ Fossil location  Europe, N. America 
   
  ■ Habitat  Shallow seas 
   
  ■ Length  Up to 7 ft 4 in (2.3 m) 
  Pterygotus was a sea scorpion that grew larger 
  than a fully grown man. Using its colossal eyes, 
  it scanned the water for prey such as fish and 
  trilobites. Perhaps it hid half-buried in sand 
  until victims wandered close by, before lashing 
  its tail to produce a violent burst of speed and 
  snatching up the animal in its claws. Fossils 
  have been found worldwide, and some experts 
  think Pterygotus not only terrorized the seas but 
  swam up rivers and into lakes as well.
  Pterygotus
  terry-GOAT-us
  Animals with jointed legs and external 
  skeletons (such as insects, spiders, and 
  scorpions) are called arthropods. Sea 
  scorpions were the largest arthropods that 
  ever lived—giant versions of the ones we 
  ﬁnd today in the yard. Today, arthropods are 
  small but in the distant past they grew  
  to greater sizes, perhaps because the Earth’s 
  air contained more oxygen, making it easier 
  for arthropods to breathe and grow.
  Key features
   
  ■ Segmented bodies and jointed limbs 
   
  ■ Hard external skeleton (exoskeleton) 
   
  ■ Pincerlike feeding claws or fangs
   
  ■ Four pairs of walking legs 
  When
  The chelicerates appeared late in the 
  Ordovician Period, about 445 millon 
  years ago. Over 77,000 identified 
  species exist today. 
  FAMILY FACT FILE
  DID YOU KNOW...?
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  45
  INVERTEBRATES
   
  ■ When  162–145 million years ago (Late Jurassic) 
   
  ■ Fossil location  Germany 
   
  ■ Habitat  Shallow ocean waters 
   
  ■ Length  Up to 3¼–3½ in (8–9 cm), without tail
  Mesolimulus is also called a horseshoe crab 
  (though it’s more closely related to spiders  
  and scorpions than crabs). It had a huge shell, 
  small, widely spaced eyes, and a stiff tail with  
  a sharp tip, like a spear. It lived on the seafloor, 
  where it hunted worms and shellfish.
  Mesolimulus
  mee-zo-LIM-you-luss
   
  ■ When  420 million years ago (Late Silurian) 
   
  ■ Fossil location  United States 
   
  ■ Habitat  Shallow seas 
   
  ■ Length  Up to 4 in (10 cm) 
  This small sea scorpion was less well armed  
  than the fearsome Pterygotus. It used prickly legs 
  to pull tiny animals toward its fangs, which it 
  then used to tear the victim to shreds. Eurypterus 
  hunted on the muddy floors of shallow seas.
  Eurypterus
  you-RIP-terruss
   
  ■ When  400–300 million years ago 
  (Silurian – Carboniferous)
   
  ■ Fossil location  Worldwide
   
  ■ Habitat  Uncertain 
   
  ■ Length  1½ in (4 cm)  
  The first scorpions lived in the sea rather  
  than on land and breathed through gills.  
  One of the oldest fossils is Proscorpius from 
  the Late Silurian Period. This creature’s  
  mouth was 
  under its 
  head like  
  that of a 
  horseshoe 
  crab, rather 
  than at the 
  front like  
  a modern 
  scorpion’s.  
  It isn’t clear 
  whether it 
  lived on land 
  or in water.
  Proscorpius
  pro-SCOR-pee-us
   
  ■ When  400 million years ago (Late Silurian) to now 
   
  ■ Fossil location  Worldwide 
   
  ■ Habitat  All land
   
  ■ Size  Up to 12 in (30 cm) across
  Although the soft and delicate bodies of spiders 
  do not fossilize well, thousands of species have 
  been found, many of them preserved in pebbles 
  of amber—a clear, golden material formed 
  from fossilized pine-tree resin. Spiders are 
  specialized hunters that often use silk traps to 
  capture prey before killing victims with a lethal 
  injection of venom from their fangs. The oldest 
  fossilized spider’s web is 100 million years old. 
  Spider
  SPY-der
  Modern horseshoe crabs such as Limulus 
  are almost exactly like their prehistoric 
  cousins from the Jurassic Period. Limulus 
  lives in shallow water off the eastern coast 
  of North America. It swims 
  upside down, as its 
  ancient relative 
  probably did.
  Pointed tail
  Limulus
  Ice age spider  
  in amber
  LIVING RELATIVE
  Abdomen
  Fossilized resin 
  from Kauri tree 
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  Giant millipede
  Millipedes were among the ﬁrst animals to walk on Earth.  
  They took their ﬁrst steps at least 428 million years ago, 
  venturing onto land to eat the few simple, mosslike land  
  plants that existed back then. By 350 million years ago, the 
  plants had evolved into trees and the millipedes had become 
  giants, too. Biggest of all was Arthropleura. As big as a crocodile, 
  it was the largest invertebrate ever to live on land.
  u THIS FOSSIL, measuring 3 in (7.1 cm) long, shows 
  just a part of one of Arthropleura’s legs.
  INVERTEBRATES
  542 million years ago
  4.6 billion years ago
  Precambrian Eon
  Cambrian
  Ordovician
  Silurian
  Devonian
  Carboniferous
  299
  359
  416
  444
  488
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  47
   
  ■ When  350 million years ago (Early Carboniferous) 
   
  ■ Fossil location  Scotland 
   
  ■ Habitat  Forests 
   
  ■ Length  Up to 8½ ft (2 m) 
   
  ■ Diet  Unknown 
  Arthropleura lived on the dark, damp floor of tropical jungles during 
  the Carboniferous Period. Fossils of its mouth have not been found, 
  making its diet a mystery, but traces of ferns in its gut suggest it was 
  a plant-eater. Although able to breathe out of water, it probably 
  stayed in damp places and may have had to return to water to shed its 
  skin as it grew. Some scientists think it could also swim under water.
  Arthropleura
  arth-row-PLOO-ra
  Millipede means “a thousand feet,”  
  but most millipedes have only 100–300 
  legs. Despite all the legs, they are slow 
  walkers, their tiny feet swinging forward 
  in waves. They feed on rotting plant 
  matter, burrowing into soil to ﬁnd it. 
  Centipedes, in contrast, are fast-moving 
  hunters that kill with venomous claws.
  LIVING RELATIVE
  INVERTEBRATES
  u CREEPY CREATURE Arthropleura’s body consisted of 
  30 segments, each with a pair of legs. Fossilized footprints show 
  it swerving around obstacles and suggest it could move quickly, 
  lengthening its stride to speed up.
  Permian
  Triassic
  Jurassic
  Cretaceous
  Paleogene
  Neogene
  251
  200
  145
  65
  23
  Now
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  48
  Insects
  Long before dinosaurs evolved, Earth was already 
  buzzing with insects. The first insects were tiny, 
  wingless creatures that lived on the ground about 
  400 million years ago. Later they evolved wings and 
  became the world’s first flying animals. Mastering 
  flight made them incredibly successful and 
  they evolved into thousands of new species. 
  Today, they make up three-quarters 
  of all animal species on Earth.
   
  ■ When  100 million years ago 
  (Early Cretaceous) to now 
   
  ■ Number of species today  Nearly 20,000
   
  ■ Diet  Nectar, pollen 
  After flowering plants appeared 125 million  
  years ago, some prehistoric wasps began to feed 
  on flowers instead of preying on other insects, 
  and these became bees. There are now thousands 
  of different types of bee. Some are solitary, but 
  many live in colonies with a single queen. 
  Worker bees rear the young and collect 
  nectar from flowers to store as honey.
   
  ■ When  110–130 million years ago 
  (Cretaceous Period) to now 
   
  ■ Number of species today  More than 
  12,000 known 
   
  ■ Diet  Everything from seeds and leaves to 
  fungi and ﬂesh
  Ants evolved from wasps that began 
  living in the ground in colonies. They 
  were rare in the age of the dinosaurs 
  but became very common later. Their 
  huge colonies have a single breeding 
  queen and hundreds of workers and 
  soldiers, all of which are wingless 
  females—daughters of the queen.  
  Ants
  DID YOU KNOW...?
  When a bee feeds on a ﬂower, 
  a yellow dust called pollen 
  sticks to its body. 
  When it lands on 
  another ﬂower, the 
  pollen rubs off and 
  causes that ﬂower to  
  produce seeds. This process  
  is known as pollination.
  Bees
  35-million-year-
  old fossil bee
  INVERTEBRATES
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  49
  Flies
   
  ■ When  230 million years ago (Triassic) to now
   
  ■ Number of species today  About 240,000 
   
  ■ Diet  Fly larvae (maggots) mostly eat rotting matter and 
  ﬂesh. Adults eat various liquid foods from nectar to blood.
  Many insects can fly, but true flies are a particular 
  family of insect that have two wings rather than 
  four. Instead of a second pair of wings, they 
  have two tiny knobs that flick back and forth to 
  stabilize flight. Flies appeared at the same time 
  as dinosaurs. Some of the early fly species almost 
  certainly pestered the dinosaurs, sucking their 
  blood and feeding on their eyes.
   
  ■ When  260 million years ago 
  (Late Permian) to now
   
  ■ Number of species today  Up to 1 million
   
  ■ Diet  Anything from pollen and nectar to fruit, ﬂesh, 
  other insects, rotting bodies, wood, and animal dung 
  Beetles evolved from flying insects that  
  once had two pairs of wings. The front pair 
  turned into hard, protective cases that folded 
  Beetles
   
  ■ When  300–350 million years ago 
  (Carboniferous Period) to now
   
  ■ Number of species today  Over 4,500
   
  ■ Diet  Rotten plant material 
  The first cockroaches looked much 
  like those alive today. They 
  scurried around on prehistoric 
  forest floors, searching with 
  their antennae (feelers) for 
  dead plants. Termites evolved 
  from wood-eating cockroaches 
  that began living in colonies.
  Cockroaches
  down over the rear wings to form  
  a shield. The first flowering plants were 
  probably pollinated by beetles. As flowering 
  plants spread and evolved into new forms,  
  so did the beetles. Today, there are so  
  many species of beetle that they may  
  well outnumber all other existing  
  animal species combined.
  FAMILY FACT FILE
  Key features
   
  ■ Three main body parts: head, 
  thorax (chest), and abdomen  
  (belly and tail) 
   
  ■ A hard, protective external  
  skeleton (exoskeleton) 
   
  ■ Three pairs of legs with joints
   
  ■ Two antennae (feelers)
   
  ■ Usually two pairs of wings
  When
  The first insects appeared in the 
  Devonian Period, 396 million years ago.
  March ﬂy
  Hydrophilus  
  (water beetle)
  Archimylacris, a 
  prehistoric cockroach
  INVERTEBRATES
  u THE BEST insect fossils are found 
  in amber – a hard, golden material 
  formed of ancient tree resin. Tree resin  
  is a thick, sticky liquid that oozes out  
  of wounded trees, often trapping  
  insects such as these ants.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  50
  Butterﬂy
  The delicate wings of butterﬂies do not fossilize easily, 
  making butterﬂy fossils rare. Even so, a few amazingly 
  well-preserved specimens have been found in very 
  ﬁne-grained rock or amber (fossilized tree resin).  
  The oldest known butterﬂies date back to about  
  65 million years ago. By 30 million years ago, 
  butterﬂies were common and very much like 
  those we see ﬂying today. 
  INVERTEBRATES
   
  ■ When  30 million years ago (Paleogene)
   
  ■ Fossil location  France 
   
  ■ Habitat  Woodland
  This species was a member of a 
  family of butterﬂy known as the 
  browns, which still exists today. Its 
  wings had bold circular marks and 
  were probably brown underneath 
  and orangey-brown on top. The 
  caterpillars would have fed on 
  grass or palm leaves, while the 
  adults sucked nectar from 
  ﬂowers using a coiled feeding 
  tube (proboscis). Like other 
  browns, but unlike other 
  insects, Lethe walked on 
  four legs rather than six.
  DID YOU KNOW...?
  Amazingly, a butterﬂy cannot taste food 
  with its mouth or antennae (feelers). Its 
  taste buds are on its feet, so it needs  
  to stand on food to taste whether it’s  
  delicious or not.
  Precambrian Eon
  Cambrian
  Ordovician
  Silurian
  Devonian
  Carboniferous
  359
  416
  444
  488
  542 million years ago
  4.6 billion years ago
  Lethe corbieri
  LEE-thee cor-bee-AIR-ee
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  51
  INVERTEBRATES
  This peacock butterﬂy has eyespots like 
  those of Lethe. Eyespots defend 
  butterﬂies from predators such as 
  birds, which peck at eyes in 
  order to strike the head. 
  Eyespots cause birds to 
  peck the wings and miss 
  the head, allowing the insect 
  to escape with only a torn wing.
  LIVING RELATIVE
  Permian
  Triassic
  Jurassic
  Cretaceous
  Paleogene
  Neogene
  251
  200
  145
  65
  23
  Now
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  52
  FOSSILIZED IN AMBER
  Millions of years ago, these insects were trapped in 
  a honey-colored goo: pine tree resin. Over time, 
  the resin hardened into amber, preserving the 
  insects so well that even the ﬁne veins in their 
  wings are visible. They look as if they lived 
  yesterday, but these fossilized insects are thought 
  to be around 38 million years old.
  d TRAPPED All kinds of insects 
  have been captured in amber, 
  including mantids such as this 
  one, and a wide variety of ﬂies.
  INVERTEBRATES
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  53
  u A WINDOW THROUGH 
  TIME The insects found in amber 
  prove that the insects we see today 
  date back millions of years.  
  Some amber fossils are more than 
  100 million years old!
  , GOLDEN GLOW Amber is a hardened, 
  fossilized material that forms from pine tree 
  resin. Pine trees produce resin from wounds in 
  the trunk. The resin ﬂows, but as it dries it 
  hardens to seal a cut in the tree’s trunk. 
  INVERTEBRATES
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  54
  Meganeura
  Possibly the largest insect that has ever lived, 
  Meganeura looked like a gigantic dragonfly. Its 
  wingspan was 2½ ft (75 cm)—12 times greater 
  than that of common dragonflies today. This 
  monster insect used its giant wings to hunt 
  other insects in midair. Insects and other 
  invertebrates grew to a great size in the 
  lush forests of the Carboniferous Period, 
  perhaps because Earth’s air was richer in 
  oxygen than today, making breathing easier.
  INVERTEBRATES
  Precambrian Eon
  Cambrian
  Ordovician
  Silurian
  Devonian
  Carboniferous
  Permian
  251
  299
  359
  416
  444
  488
  542 million years ago
  4.6 billion years ago
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  55
   
  ■ When  300 million years ago (Late Carboniferous) 
   
  ■ Fossil location  Europe
   
  ■ Habitat  Tropical swamp forests 
   
  ■ Wingspan  Up to 30 in (75 cm) 
  Meganeura was not a true dragonfly but a 
  member of a closely related family called 
  griffinflies. It had stronger legs than modern 
  dragonflies and a simpler pattern of veins in its 
  wings. It flew quickly through tropical forests, 
  using its huge compound eyes to spot prey. It 
  could snatch flying insects in midair, grabbing 
  them with its legs and bringing them up to its 
  mouth to devour as it flew.
  Meganeura
  MEGA-new-ra
  u VEINS IN WINGS
  Meganeura means “large-veined.” This fossil, 
  found in France, shows the thick veins that  
  acted as struts to stiffen the large, delicate wings.
  u WINGED WONDER
  Like modern dragonflies, Meganeura flapped 
  its front and rear wings separately and perhaps at 
  different speeds, giving it a fine control of flight. 
  Dragonflies are amazingly agile, able to hover, fly 
  backward, and change direction in an instant.
  INVERTEBRATES
  One of the world’s largest dragonﬂies  
  today is the giant dragonﬂy (Petalura 
  gigantea), which is found in New 
  South Wales, Australia. Despite 
  having a 
  wingspan of 
  almost 5½ in 
  (14 cm), it is 
  actually quite a 
  poor ﬂyer, and rarely  
  moves far from its area. 
  Like its ancestors, it 
  eats ﬂying insects.
  LIVING RELATIVE
  Triassic
  Jurassic
  Cretaceous
  Paleogene
  Neogene
  200
  145
  65
  23
  Now
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  56
  Ammonites
  Ammonite fossils are unmistakeable, thanks to their 
  beautiful coiled shapes. These sea creatures were close 
  relatives of today’s octopuses and squids but lived inside 
  a shell, which they enlarged with new chambers as they 
  grew, forming a spiral. They lived throughout the seas 
  and swam by squirting water, the hollow inner chambers 
  of their shells acting as air tanks to help them float.
  Rib
  Marston marble
   
  ■ When  200 million years ago (Early Jurassic) 
   
  ■ Fossil location Worldwide 
   
  ■ Habitat  Seas 
   
  ■ Size  Up to ¾ in (2 cm) across  
  Vast numbers of Promicroceras died at 
  the same time, carpeting the seafloor 
  with shells. Over time, these turned 
  into fossils, forming an amazing type 
  of rock called Marston marble, 
  which consists of almost nothing  
  but ammonites. The cause of the 
  mass death is a mystery, but one 
  possibility is poisoning of seawater 
  by algae (microscopic plants).
  Promicroceras
  pro-my-CROSS-e-ras
   
  ■ When  144–65 million years ago (Late Cretaceous) 
   
  ■ Fossil location  Europe, Africa, India, 
  N. America, S. America 
   
  ■ Habitat  Shallow seas 
   
  ■ Size  Up to 8 in (20 cm) across 
  Scaphites was an unusual ammonite. Instead of 
  forming a neat spiral, its shell grew in a crooked 
  shape. As a result, the opening for its head would 
  have gotten tighter and tighter as Scaphites grew, 
  eventually starving the animal to death. Perhaps 
  Scaphites only lived long enough to lay its eggs, 
  dying soon after, as happens in octopuses.
  Scaphites
  scaff-EYE-tees
   
  ■ When  200 million years ago (Early 
  Jurassic) 
   
  ■ Fossil location Worldwide 
   
  ■ Habitat  Seas 
   
  ■ Size Up to 2½ in (6 cm) across 
  Echioceras had a tightly 
  coiled shell, which may 
  have made it difficult 
  to move rapidly.  
  It preyed  
  on other  
  slow-moving 
  creatures in the 
  Jurassic seas.
  INVERTEBRATES
  Scaphites fossil
  FAMILY FACT FILE
  Key features
   
  ■ Coiled shell divided into chambers
   
  ■ Soft body inside the outermost 
  chamber
   
  ■ Large head and well-developed eyes
   
  ■ Long tentacles for capturing prey 
  When
  Ammonites appeared 425 million years 
  ago and were very common in the oceans 
  throughout the age of the dinosaurs. 
  They perished at the same time as the 
  dinosaurs, 65 million years ago.
  Echioceras
  ECK-ee-oh-se-ras
  The shell’s outermost 
  chamber housed the 
  ammonite’s soft body.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  57
  57
   
  ■ When  200 million years ago (Early Jurassic) 
   
  ■ Fossil location  Europe 
   
  ■ Habitat  Open seas 
   
  ■ Size  1¼ in (3 cm) across 
  Bifericeras fed on small invertebrates 
  that lived in the seas. The larger shells 
  (“macroconches”) belonged to the females  
  and the smaller ones (“microconches”) to  
  the males. Females needed larger body  
  sizes for producing 
  and protecting  
  their eggs. 
  Bifericeras
  BYE-fuh-ih-suh-ras
  LIVING RELATIVE
   
  ■ When  65–23 million years ago 
  (Paleogene to Early Neogene) 
   
  ■ Fossil location Worldwide 
   
  ■ Habitat  Open waters 
   
  ■ Size Up to 6 in (15 cm) across 
  Although the ammonites 
  died out at the same time 
  as the dinosaurs, closely 
  related animals called 
  nautiloids survived. 
  Aturia was a fast-
  swimming nautiloid that 
  probably preyed on ﬁsh 
  and shrimp. Its shell was 
  smooth and streamlined for 
  speed, without the ribs seen in 
  many ammonites.
  The pearly nautilus is a 
  living nautiloid and 
  a relative of the 
  ammonites. 
  Like its 
  prehistoric 
  cousins, it 
  lives in a 
  spiral shell 
  divided into 
  chambers, and it 
  swims by squirting 
  water. It has up to 90 
  tentacles, which it uses to 
  capture small ﬁsh and crustaceans.
  Macroconch (female)
  Microconch 
  (male) fossil 
  formed of the 
  mineral iron 
  pyrite (“fool’s 
  gold”).
  Aturia
  ay-TOO-ree-a
  INVERTEBRATES
  Because the shell’s air-ﬁlled 
  inner chambers ﬂoated 
  upward, ammonites  
  swam with their heads 
  beneath their bodies.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  58
  INVERTEBRATES
  INVERTEBRATES
  Rare jewels
  In 1981, the  
  World Jewellery 
  Confederation gave 
  oﬃcial gemstone 
  status to a brightly 
  colored mineral 
  found only on the 
  surface of certain 
  ammonite fossils. It is 
  thought to be one of 
  the rarest gemstones 
  on the Earth, rivaling red 
  diamond. It is found only in  
  a few parts of the Rocky 
  Mountains in North America 
  and used to make exclusive 
  luxury jewelry. 
  Fossil gems
  Ammonite fossils can be as beautiful  
  as jewels. Some look like glass ornaments 
  when they are cut open and polished, 
  their once-hollow shells having ﬁlled  
  up with crystalline minerals over 
  millions of years. Others have a  
  pearly surface that shimmers with 
  color, forming one of the world’s 
  most precious gemstones.
  d AMMONITES GREW in a 
  spiral shape, adding new chambers 
  to their shell as they got bigger. This 
  fossil of the ammonite Desmoceras 
  is about 100 million years old. 
  PEARLY AMMONITES
  Ammonites made their shells from the  
  mineral aragonite – the shiny mineral from 
  which pearls form. In most fossils the shell 
  has entirely disappeared and all that remains 
  is a mould of its hollow interior. However, 
  some ammonite fossils retain a pearly ﬁlm  
  of aragonite on the surface. In the best 
  specimens, this delicate layer produces 
  shimmering colours by splitting reﬂected  
  light, a phenomenon known as iridescence.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  INVERTEBRATES
  INVERTEBRATES
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  60
  Fossil seashells
  The seashells on these pages might look like a 
  collection found on a beach, but these are all fossil 
  shells and are millions of years old, some dating back 
  to before the dinosaurs. Seashells fossilize well because 
  they are so hard. They are among the easiest fossils  
  to find. Most are shells of 
  mollusks—soft-bodied 
  invertebrates such  
  as snails and clams.
  FAMILY FACT FILE
  Gastropods
  All the spiral shells on 
  these pages were made by 
  sea-dwelling gastropods (the 
  class of mollusks 
  that includes 
  snails, slugs, 
  and limpets). 
  Just like garden 
  snails, shelled 
  gastropods can 
  hide inside or 
  under their shells  
  for protection. The soft body 
  within consists mainly of a 
  single large muscular foot. 
  Bivalves
  These mollusks have  
  two shells joined by  
  a hinge so they can 
  snap shut. Cockles, 
  clams, scallops, 
  mussels, and oysters  
  are all bivalves.
  When
  Mollusks date back some 500 million 
  years to the Cambrian Period.
  INVERTEBRATES
  Carrier shell (Xenophora)
  Pliocene
  Saltwater clam  
  (Gervillaria) 
  Cretaceous
  Top shell 
  (Calliostoma)
  Eocene
  Snail
  Comb shell (Murexsul )
  Pliocene
  Wentletrap 
  (Cirsotrema)
  Pliocene
  Beak shell 
  (Rimella)
  Eocene
  Bubble shell (Bulla)
  Pleistocene
  Giant cerith (Campanile)
  Eocene
  Fan mussel 
  (Pinna)
  Jurassic
  Nut clam (Nuculana)
  Eocene
  Scallop (Oxytoma)
  Early Jurassic
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  61
  INVERTEBRATES
  Fig shell 
  (Ficopsis)
  Eocene
  Sea snail 
  (Ecphora)
  Pliocene
  Sea snail 
  (Euomphalus)
  Carboniferous
  Jewel-box shell 
  (Chama)
  Eocene
  Sundial shell 
  (Granosolarium)
  Eocene
  Sundial shell 
  (Granosolarium)
  Eocene
  Basket shell (Fimbria)
  Eocene
  Scallop (Pecten)
  Miocene
  Whelk 
  (Neptunea)
  Pliocene
  Cone shell 
  (Conus)
  Eocene
  Cockscomb oyster 
  (Rastellum)
  Cretaceous
  Sea snail (Clavilithes)
  Eocene
  Nerite (Velates)
  Eocene
  Venus shell (Chione)
  Miocene
  Horse mussel (Modiolus)
  Cretaceous
  Cockle (Acrosterigma)
  Pliocene
  Hooded ark shell 
  (Cucullaea)
  Cretaceous
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  62
  EARLY
  VERTEBRATES
  u PHLEGETHONTIA This early 
  vertebrate may look like a snake, but it was 
  a legless amphibian. It grew to lengths of 
  about 28 in (70 cm) and hunted small 
  prey using spiked teeth.
  EARLY VERTEBRATES
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  63
  Vertebrates are animals 
  with backbones. Fish were 
  the ﬁrst vertebrates; they 
  appeared in Earth’s oceans 
  more than 500 million 
  years ago. These ﬁrst ﬁsh 
  were jawless and very 
  diﬀerent from today’s ﬁsh. 
  EARLY VERTEBRATES
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  64
  What are vertebrates?
  A donkey, a crocodile, a ﬁsh, a parrot, and a frog all have one thing in common.  
  They all have a backbone, or vertebral column, connected to a supporting bony 
  skeleton inside their bodies. They are all vertebrates.
  Vertebrates can be divided into ﬁve groups: mammals, birds, 
  reptiles, amphibians, and ﬁsh.
  FAMILY TREE OF 
  VERTEBRATES 
  Although vertebrates are the animals we 
  know most about, they actually make up 
  just a tiny part of the animal kingdom. 
  Vertebrates with limbs—tetrapods—are 
  all descended from ﬁsh. 
  MAMMALS
  BIRDS
  d AFRICAN ELEPHANT The largest living 
  land mammal in the world, a male African 
  elephant can stand 13 ft (4 m) at the shoulder.
  There are almost 
  10,000 species of 
  bird. They are the 
  living descendants 
  of dinosaurs, but 
  they developed the 
  ability to ﬂy. Feathers  
  help them to ﬂy, but  
  also keep them warm.
  Mammals can be divided into 
  three groups, depending on 
  their means of reproduction. 
  Placental mammals 
  give birth to 
  well-developed 
  young. Marsupials 
  give birth to 
  undeveloped young. 
  Monotremes (there 
  are just ﬁve living 
  species) lay eggs.
  ,  GERBIL Rodents 
  are a large group of 
  mammals, 
  characterized 
  by large incisors, 
  perfect for gnawing.
  Chimpanzee
  u PEREGRINE 
  FALCON This is one of 
  the fastest of all animals.
  EARLY VERTEBRATES
  . COMMON RHEA Not all 
  birds can ﬂy. In fact, more than  
  40 species of bird, like  
  this rhea, have lost 
  the ability to ﬂy.
  Budgerigar
  Fish
  Amphibians
  Mammals and 
  relatives
  Turtles and 
  tortoises
  Ichthyosaurs
  Plesiosaurs  
  (marine reptiles)
  Lizards and 
  snakes
  Crocodiles and 
  relatives
  Pterosaurs 
  (ﬂying reptiles)
  Dinosaurs 
  and birds 
  Tetrapods
  Reptiles
  Archosaurs
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  65
  REPTILES
  AMPHIBIANS
  FISH
  Along with some amphibians, reptiles 
  were the ﬁrst vertebrates to live 
  entirely on land. Their skin is dry and 
  covered in 
  scales to help 
  retain water,  
  a necessary 
  adaptation, since many 
  reptiles live in warm areas 
  with limited access to water. 
  Earth’s ﬁrst 
  vertebrates—ﬁsh—
  now form more 
  than half of all 
  vertebrate species.  
  Gills allow them to 
  breathe underwater.
  Modern amphibians have moist, soft 
  skin, and most amphibians can absorb 
  oxygen through this skin in addition to 
  having lungs. They largely live on land 
  but require damp conditions. Most have  
  to return to water to lay eggs.
  . BONE is a lightweight, living organ, and it is 
  found only in vertebrates. Because it is supplied 
  with blood vessels, it can grow (unlike the hard 
  casing of an invertebrate such as a crab, which has 
  to be shed to allow growth).
  EARLY VERTEBRATES
  TAKE A LOOK—A PEEP INSIDE
  Vertebrates have a backbone and internal bony 
  skeleton. They also have a highly developed 
  nervous system, and a larger brain for body size 
  than invertebrates. Blood is pumped around the 
  body by the heart, supplying the vertebrate’s 
  body with food and oxygen and removing waste 
  products. They breathe using lungs.
  Skeleton of 
  Maiasaura, 
  a duck-billed 
  dinosaur.
  Backbone
  Parson’s 
  chameleon
  . MILK SNAKE 
  Some species of reptile 
  have to shed their skin 
  as they grow. They do 
  this between four and 
  eight times a year.
  d CAIMAN 
  Crocodilians, such as the 
  caiman below, have thrived 
  since they appeared with 
  early dinosaurs, some  
  200 million years ago.
  d POISON 
  DART FROG There are some 
  4,500 species of frog and toad, 
  including about 120 species of 
  poison dart frog.
  . FIRE SALAMANDER 
  This salamander will curl up 
  underground in colder, winter 
  months. Its bright color warns 
  predators it is poisonous.
  , CHINESE GIANT 
  SALAMANDER 
  (the world’s largest 
  living amphibian).
  d  STAYING TOGETHER Many ﬁsh swim 
  in schools, ﬁnding safety in numbers.
  d WHALE SHARK This is the world’s largest 
  ﬁsh. Despite its size, it feeds on plankton—tiny 
  organisms that drift in water.
   Spiny puﬀer ﬁsh
  Human 
  skeleton
  Backbone
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  66
  Jawless fish
  The first vertebrates were fish, but they were very 
  different from today’s fish. The early fish couldn’t 
  bite, since jaws were yet to evolve. Instead, they fed 
  by sucking or scraping. With few or no fins, they 
  swam by waggling their tails like tadpoles. They had 
  no internal bones, but some had wide, bony shields 
  covering their heads—protection from  
  predators such as giant sea scorpions.
   
  ■ When  410 million years ago (Early Devonian) 
   
  ■ Fossil location  Europe 
   
  ■ Habitat  Ocean ﬂoor 
   
  ■ Length  14 in (35 cm) 
  With its flat, paddle-shaped head  
  and narrow body, Drepanaspis was 
  a strangely shaped fish. It hunted for  
  food near the bottom of Devonian seas. 
  Drepanaspis’s feeding methods are 
  a mystery, since its jawless mouth  
  faced upward instead of downward,  
  a curious feature that would have  
  made it difficult to scoop in food. Like 
  many other jawless fish, Drepanaspis had 
  bony armor to protect it from attack. 
  Drepanaspis
  DREP-an-ASP-iss
  Two groups of jawless ﬁsh still exist  
  today: hagﬁsh and lampreys. Both are 
  eel-shaped creatures with no bones, scales, 
  or ﬁns. Hagﬁsh feed on worms or dead sea 
  animals. Some lampreys are parasites – they 
  use their circular, jawless mouths to latch on 
  to ﬁsh so they can feed on their blood.
  LIVING RELATIVE
  Toothed mouth 
  of a lamprey
  EARLY VERTEBRATES
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  67
  FAMILY FACT FILE
  Key features
   
  ■ Mouths but no jaws 
   
  ■ Many species lacked paired fins
   
  ■ Usually no stomach
   
  ■ Swam by beating a muscular tail 
  When
  Some jawless fish fossils have been dated 
  to the Cambrian Period, more than  
  500 million years ago. Many jawless fish 
  died out at the end of the Devonian 
  Period, almost 350 million years ago.
   
  ■ When  410 million years ago (Early Devonian) 
   
  ■ Fossil location Europe 
   
  ■ Habitat  Freshwater pools and streams 
   
  ■ Length  9 in (22 cm) 
  This small fish lived at the bottom of pools or 
  streams. Perhaps it moved its broad head-shield 
  from side to side, stirring up mud as it searched 
  for hidden worms and other creatures. It may 
  also have fed on the waste of other animals  
  that lived in the water. Pairs of scaly flaps 
  balanced its body, and a fin on its back 
  prevented it from rolling over.
  Cephalaspis
  SEFF-a-LASP-iss
   
  ■ When  490 million years ago (Early Ordovician) 
   
  ■ Fossil location  Bolivia 
   
  ■ Habitat  Coastal waters 
   
  ■ Length  12 in (30 cm) 
  This fish had a broad head-shield and a body 
  that narrowed to end in a small fin. With this 
  shape, it probably swam very much like a 
  tadpole, sucking in scraps of food through  
  its ever-open mouth. Sacabambaspis had 
  sense organs that helped it to feel movement  
  in the water, allowing it to judge the distance  
  to its prey—and avoid predators.
  Sacabambaspis
  SAC-a-bam-BASP-iss
   
  ■ When   410 million years ago (Early Devonian) 
   
  ■ Fossil location  Europe 
   
  ■ Habitat  Shallow seas and river mouths 
   
  ■ Length  10 in (25 cm) 
  Zenaspis
  zen-ASP-iss
   
  ■ When  425 million years ago (Middle Silurian)
   
  ■ Fossil location  Europe 
   
  ■ Habitat  Freshwater pools and streams 
   
  ■ Length  2 in (6 cm) 
  Although Birkenia did not have fins, it 
  was still an active swimmer in the pools  
  and streams in which it lived. It fed on  
  the remains of dead plants and animals, 
  probably sucking in scraps with its gaping 
  mouth. Unlike many other jawless fish that 
  had bony head-shields, Birkenia’s head was 
  covered in small scales. 
  Birkenia
  bir-KEEN-ee-a
  Eye
  Zenaspis had a horseshoe-shaped head 
  protected by an armored shield, while the  
  rest of its fairly flat body was protected by 
  scales. Its eyes were placed close together on  
  top of its head (a perfect position for spotting 
  predators for a bottom-dwelling fish). Like  
  lots of jawless fish, Zenaspis did not have 
  teeth. Instead, its mouth, located on the 
  underside of the body, was lined with bony 
  plates. It probably fed on small creatures 
  found on the seafloor or in river mouths. 
  EARLY VERTEBRATES
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  68
  Armored ﬁsh
  Also known as placoderms, the armored ﬁsh were  
  the ﬁrst ﬁsh to grow to a monstrous size, some 
  reaching the size of modern sharks. They were also 
  among the ﬁrst ﬁsh with biting jaws, which they 
  used as lethal weapons. For protection from each  
  other, these prehistoric ﬁsh evolved suits of armor  
  made of overlapping plates of bone. 
   
  ■ When  Almost 410 million years ago (Early Devonian) 
   
  ■ Fossil location  Germany 
   
  ■ Habitat  Shallow seas 
   
  ■ Length  10–12 in (25–30 cm) 
  A small, ﬂat-bodied ﬁsh with a narrow tail, 
  Gemuendina looked similar to the modern 
  stingray except that its mouth was on top of 
  its head. Unlike other armored ﬁsh, it did not 
  have plates of bone in its mouth. Instead, it 
  used star-shaped scales to grasp prey.
  Gemuendina
  JEM-yoo-en-DEE-na
   
  ■ When  Nearly 380 million years ago (Late Devonian) 
   
  ■ Fossil location  USA, Europe, Morocco 
   
  ■ Habitat  Shallow seas 
   
  ■ Length  20 ft (6 m) 
  Sometimes described as the Tyrannosaurus of 
  the seas, Dunkleosteus was one of the largest 
  armored ﬁsh. It was as big as an elephant and a 
  vicious hunter, with the most powerful 
  bite of any ﬁsh (except perhaps the 
  megatooth shark). Instead of 
  teeth, Dunkleosteus had a 
  kind of beak formed of 
  bony plates with sharp 
  points. Some 
  Dunkleosteus fossils 
  have bite marks 
  matching these 
  jaws, suggesting the 
  killer was also a 
  cannibal.
  Dunkleosteus
  DUN-kell-OSS-tee-us
  u MONSTER JAWS Dunkleosteus had a 
  massive head and large, scissorlike jaws with 
  razor-sharp bony plates that formed a “beak.”  
  Its bite was powerful enough to crack concrete.
  EARLY VERTEBRATES
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  FAMILY FACT FILE
  Key features
   
  ■ Armor-plated bodies
   
  ■ Jaws with bony plates that served  
  as teeth
   
  ■ Joints between armor plates allowed 
  the jaws to open and the body to bend
  When
  Armored fish lived from the Late Silurian 
  Period, nearly 430 million years ago, to 
  the end of the Devonian Period, 359 
  million years ago.
   
  ■ When  380 million years ago (Late Devonian) 
   
  ■ Fossil location  Australia 
   
  ■ Habitat  Reefs 
   
  ■ Length  12 in (30 cm)  
  Rolfosteus was quite bizarre to look at, with 
  a long, tubelike snout like a unicorn’s horn. 
  Scientists are puzzled over the use of the 
  snout. Rolfosteus may have used it to dig 
  through the sandy seabed to look for hidden 
  Rolfosteus
  ROLL-foss-tee-us
   
  ■ When  380–350 million years ago 
  (Middle to Late Devonian) 
   
  ■ Fossil location  N. America, Europe 
   
  ■ Habitat  Shallow waters 
   
  ■ Length  16 in (40 cm)  
  Coccosteus
  cock-oh-STEE-us
  Although quite small in size, Coccosteus was 
  an eﬀective predator. It hunted other ﬁsh, 
  perhaps lying in wait on the seabed for its  
  prey before ambushing. Like Dunkleosteus, it 
  had a beaklike mouth, with sharp, bladelike 
  edges to tear ﬂesh oﬀ larger animals. Its fossils 
  show that it had a powerful tail, suggesting 
  that it was a strong swimmer.
  prey, or it may have been a male ornament 
  used to attract females. Like other armored 
  ﬁsh, this creature had no teeth. Instead, it  
  had ﬂattened plates of bone at the back of  
  its mouth. These may have been used to crush 
  the shells of crabs and other crustaceans.
  EARLY VERTEBRATES
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  70
  EARLY VERTEBRATES
  Sharks and rays
  Fossil teeth reveal that killer sharks have been cruising  
  the seas for more than 400 million years—an astonishing  
  length of time. Along with their ﬂat-bodied relatives the rays, 
  sharks belong to a truly ancient class of animals known as 
  cartilaginous ﬁsh. These ﬁsh have no bones; instead, the 
  skeleton is made of a rubbery material called cartilage.
   
  ■ When  Late Permian to Late Cretaceous
   
  ■ Fossil location  Europe, N. America, Asia, Africa
   
  ■ Habitat  Oceans
   
  ■ Length  6 ft (2 m) 
   
  ■ Diet  Small marine animals  
  Hybodus looked as ﬁerce as any modern shark 
  and had the classic streamlined shape, but its 
  teeth and ﬁns were diﬀerent from today’s 
  Hybodus
  hy-BODE-us
   
  ■ When  54–38 million years ago 
  (Early to Middle Paleogene)
   
  ■ Fossil location  USA
   
  ■ Habitat  Freshwater streams and lakes 
   
  ■ Length  3 ft (1 m) 
   
  ■ Diet  Crayﬁsh, shrimp, and other invertebrates
  Heliobatis may have been a relative of the stingray. 
  Heliobatis
  he-lee-oh-BAT-iss
  FAMILY FACT FILE
  Key features
   
  ■ Teeth are continuously shed and 
  replaced 
   
  ■ Skeleton made of cartilage
   
  ■ No ribs whatsoever
   
  ■ No air bladder for controlling buoyancy
   
  ■ Sharks must keep swimming or they  
  will sink
   
  ■ Fins in pairs for steering, unlike  
  earlier fish 
  When
  The earliest known fossils of sharks  
  and rays date back to the Late Silurian, 
  almost 420 million years ago.
  sharks. It had two types of tooth: sharp ones  
  at the front for seizing slippery prey such as 
  ﬁsh, and ﬂatter, more blunt teeth at the back 
  of the mouth for crushing shells. In front of 
  Hybodus’s dorsal ﬁn (the ﬁn on its back) was a 
  long, bladelike spine. This may have helped 
  the ﬁn to cut through the water more easily  
  or it may have been used for defense.
  Its tail contained up to three needlelike stingers 
  that may have been able to inject venom.  
  It lived at the bottom of lakes and possibly 
  rivers, where it hunted for crayﬁsh, small ﬁsh, 
  and possibly snails. It was named Heliobatis 
  (“Sun ray”) because of the way its ﬁns fan  
  out around it like rays of sunlight.
  Huge 
  pectoral 
  ﬁn
  Dorsal ﬁn
  Spine
  Gill slits
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  71
  EARLY VERTEBRATES
   
  ■ When  105–65 million years 
  ago (Mid to Late Cretaceous) 
   
  ■ Fossil location  Worldwide 
   
  ■ Habitat  Oceans 
   
  ■ Length  15 ft (4.5 m) 
   
  ■ Diet  Marine creatures 
  Fossilized shark teeth are 
  common, since sharks shed 
  thousands of teeth during 
  their lives. Many Squalicorax 
  teeth have been found, including one embedded 
  in the foot of a hadrosaurid dinosaur. The rare 
  find shows that Squalicorax sometimes scavenged 
  from carcasses washed into the sea.
   
  ■ When  56 million years ago to now 
   
  ■ Fossil location  Worldwide
   
  ■ Habitat  Cool, shallow marine waters 
   
  ■ Length  10 ft (3 m) 
   
  ■ Diet  Sharks, rays, ﬁsh, seals, 
  and dead animals 
  Also known as the seven gill 
  shark, Notorynchus had seven 
  gill slits (unlike the five seen in 
  most sharks). Its strange teeth were 
  each made up of many small points (cusps), 
  creating a jagged, sawlike edge ideal for  
  slicing flesh. Notorynchus is still found today 
  and is common in cooler seas worldwide.
  Squalicorax
  SKWA-lih-CORE-ax
  Notorynchus
  no-toe-RIN-cuss
   
  ■ When  Early Permian
   
  ■ Fossil location  Worldwide
   
  ■ Habitat  Oceans 
   
  ■ Length  18 ft (5.5 m) 
   
  ■ Diet  Marine animals  
  This bizarre shark was named Helicoprion 
  (“spiral saw”) because the teeth of its 
  lower jaw grew in a spiral, 
  forming a disk as big 
  Helicoprion
  HELL-ee-coe-PRY-on
   
  ■ When  Late Devonian 
  to Early Carboniferous
   
  ■ Fossil location 
  N. America, Scotland 
   
  ■ Habitat  Oceans
   
  ■ Length  5 ft (1.5 m) 
   
  ■ Diet  Marine animals  
  One of the oddest  
  of all prehistoric fish, 
  Stethacanthus had a dorsal fin 
  shaped like an ironing board, with a 
  cluster of toothlike scales (denticles)  
  on top. It had more toothlike scales on 
  its head, and its side fins had long, pointed 
  rods called whips trailing behind them. These 
  features may have been present only in males 
  Stethacanthus
  steth-a-CAN-thus
  and were perhaps important in mating. 
  Stethacanthus usually lurked in shallow, 
  coastal waters, where it nosed around  
  for small fish and shellfish.
  Cusp
  Old teeth in 
  middle of spiral
  as a dinner plate. Only Helicoprion’s teeth have 
  been found. The disk is known to be from the 
  lower jaw, but how the shark used it to feed is 
  a mystery.
  Single Notorynchus tooth
  Dorsal fin
  Whip
  Denticles
  New teeth grew  
  on the outside
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  Megatooth shark
  The megatooth shark may have been the most terrifying and 
  ferocious predator of all time—and possibly the biggest. This  
  gigantic beast was a close cousin of today’s great white shark but  
  was far larger: the height of its tail fin alone was equal to the length 
  of a great white. The megatooth terrorized the seas for more than  
  20 million years, preying on whales, dolphins, and seals. It attacked 
  at speed, seizing victims in its vast jaws and crushing them or  
  shaking them to pieces.
  EARLY VERTEBRATES
  A fully grown megatooth was more than  
  times heavier than the great white, the 
  largest shark alive today.
  Record Breaker
  Precambrian Eon
  Cambrian
  Ordovician
  Silurian
  Devonian
  Carboniferous
  Permian
  251
  299
  359
  416
  444
  488
  542 million years ago
  4.6 billion years ago
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  73
  u FOSSIL JAWS of the megatooth shark have 
  never been found, but scientsists built the model 
  above by scaling up a great white shark’s jaws (in 
  center). The megatooth’s bite was five times more 
  powerful than that of Tyrannosaurus—it could 
  have crushed prey to death with a single bite.
   
  ■ When  25–1.5 million years ago (Late Paleogene to 
  Early Neogene) 
   
  ■ Fossil location  Europe, N. America, S. America, 
  Africa, Asia 
   
  ■ Habitat  Warm oceans 
   
  ■ Length  67 ft (20 m) 
  Only teeth and spine bones of the megatooth 
  shark have been found. By comparing these 
  with modern sharks, scientists estimate the 
  megatooth shark may have weighed as much 
  as 100 tonnes—as much as 30 elephants.  
  Its fossil teeth are common in sites rich in  
  sea mammals such as seals and dolphins, 
  suggesting these were the megatooth’s prey.
  Megatooth shark
  MEG-a-tooth shark
  Megatooth means “big tooth.” This  
  shark certainly lived up to its name,  
  with more than 250 teeth, 
  each of which grew up 
  to 7 in (17 cm) long. 
  The teeth had sharp, 
  serrated edges like 
  the cutting side of  
  a saw—ideal for 
  slicing through ﬂesh.
  BIG TOOTH
  EARLY VERTEBRATES
  Triassic
  Jurassic
  Cretaceous
  Paleogene
  Neogene
  200
  145
  65
  23
  Now
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  74
  EARLY VERTEBRATES
  Bony ﬁsh
  About 400 million years ago, a new family of ﬁsh  
  began swimming in the seas. Unlike the sharks 
  that had ruled the waters for millions of years, 
  the new ﬁsh had skeletons hardened with calcium 
  to form bone, earning them the name “bony ﬁsh.”  
  The bony ﬁsh evolved into a huge range of new species 
  and make up more than 95% of ﬁsh species alive today.
  FAMILY FACT FILE
   
  ■ When 112–70 million years ago (Middle to Late Cretaceous) 
   
  ■ Fossil location  N. America 
   
  ■ Habitat  Shallow waters of N. America 
   
  ■ Length  20 ft (6 m) 
  Xiphactinus was a powerful swimmer with a 
  long, muscular body. It had a huge mouth and 
  could swallow large prey whole. One fossil was 
  found to contain the remains of a 7 ft (2 m)  
  ﬁsh in its stomach—perhaps the prey was  
  too big for Xiphactinus and killed it by 
  thrashing around inside.
  Xiphactinus
  zye-FAC-tee-nus
   
  ■ When  176–161 million years ago (Middle Jurassic) 
   
  ■ Fossil location  Europe, Chile 
   
  ■ Habitat  Oceans 
   
  ■ Length  30 ft (9 m)  
  Perhaps the largest bony ﬁsh that ever lived, 
  Leedsichthys was bigger than a killer whale. 
  Despite its fearsome size, it was a harmless 
  ﬁlter feeder rather than a hunter—it 
  Leedsichthys
  LEEDS-ick-thiss
  gulped huge volumes of water into its  
  mouth and then squirted it out while sifting 
  shrimp and other tiny animals with its gills. 
  Bite marks on one fossil show that Leedsichthys 
  was hunted by gigantic marine reptiles 
  called pliosaurs.
  Key features
   
  ■ A skeleton made of bone
   
  ■ Most have ray fins (fins supported by 
  long rays of bone that give these fish fine 
  control of movement)
   
  ■ Swim bladders (air-filled sacs) to help 
  these fish stay buoyant in water
  When
  Bony fish first appeared in the Devonian 
  Period, almost 395 million years ago, and 
  remain very common today.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  75
  EARLY VERTEBRATES
   
  ■ When  55–34 million years ago (Middle to Late Paleogene) 
   
  ■ Fossil location  USA, Lebanon, Syria, 
  S. America, Africa 
   
  ■ Habitat  Lakes 
   
  ■ Length  26 in (65 cm)  
  A relative of herrings and sardines, Diplomystus 
  lived in freshwater rivers and lakes. Many of the 
  Diplomystus
  DIP-low-MISS-tus
  best-preserved fossils have been found in  
  the Green River region of Wyoming. These 
  show that Diplomystus was a predator—a 
  number of smaller ﬁsh have been found preserved 
  in the stomachs. This creature had an upward-
  facing mouth, suggesting that it hunted ﬁsh  
  that swam just below the surface of the water.
   
  ■ When  55–33 million years ago (Middle to Late Paleogene) 
   
  ■ Fossil location  N. America 
   
  ■ Habitat  Freshwater streams and lakes 
   
  ■ Length  6 in (15 cm)    
  Priscacara lived in deep lakes in North 
  America, where its fossils formed in mud  
  on the lake ﬂoor, preserved in beautiful  
  detail. The stiﬀ spines of its ﬁns may have 
  been defensive weapons—they would 
  probably have stabbed the mouth of any 
  predator that tried to swallow Priscacara.
  Priscacara
  PRISS-ca-carr-a
   
  ■ When  56–49 million years ago (Paleogene) 
   
  ■ Fossil location  Italy 
   
  ■ Habitat  Oceans
   
  ■ Length  3 in (8 cm)  
  This fossil ﬁsh is a very close relative of modern 
  unicorn ﬁsh, which are so named because they 
  have a spike on the forehead like a unicorn’s 
  horn. Like its modern relatives, this prehistoric 
  species may have lived in shoals on coral reefs.
  Naso
  NAY-zoe
   
  ■ When  55–37 million years ago (Middle to Late Paleogene) 
   
  ■ Fossil location  USA 
   
  ■ Habitat  Shallow waters 
   
  ■ Length  12 in (30 cm) 
  This ancient ﬁsh of the perch family looked  
  just like its modern relative. Its body was 
  covered in scales. On its humped back were two 
  ﬁns bearing sharp spines that it raised to scare 
  away predators. Like many perches today, it may 
  have had a striped body that helped it blend in 
  with the reeds and 
  bulrushes 
  among which 
  it hid from 
  predators.  
  It moved in 
  shoals, feeding on 
  insects, ﬁsh eggs,  
  and small ﬁsh.
  Perca
  PER-ca
  Upward-facing 
  mouth
   
  ■ When 55–40 million years ago (Middle Paleogene) 
   
  ■ Fossil location USA 
   
  ■ Habitat  Oceans 
   
  ■ Length  10 in (25 cm) 
  This incredible fossil shows a Mioplosus 
  caught in the act of devouring its prey.  
  The victim must have become lodged in the 
  predator’s mouth, killing it. Mioplosus was a 
  hunter that preyed on ﬁsh up to half its size, 
  using pointed teeth to trap them in its jaws.
  Mioplosus
  MY-oh-PLOH-sus
   
  ■ When  55–34 million years ago (Middle to 
  Late Paleogene) 
   
  ■ Fossil location  USA 
   
  ■ Habitat  Rivers and lakes of N. America 
   
  ■ Length  10 in (25 cm)   
  Scientists have discovered skeletons of  
  Knightia in the stomachs of many larger ﬁsh. 
  Huge shoals must have crowded the ancient 
  seas, making them easy prey. Hundreds of 
  well-preserved Knightia fossils have been 
  found in the Green River region of Wyoming. 
  The State of Wyoming declared Knightia as 
  its state fossil in 1987.
  Knightia
  NITE-ee-ah
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  76
  This bony fish appears to have been a food choice of a 
  ferocious dinosaur called Baryonyx, as a number of Lepidotes 
  scales and bones have been found in the fossilized stomach 
  area of this dinosaur. It was quite big 
  itself, reaching lengths of up to 6 ft  
  (1.8 m), and it was widespread— 
  fossil remains have been found 
  all over the world.
  Lepidotes
   
  ■ When  199—70 million years ago (Jurassic to Early Cretaceous) 
   
  ■ Fossil location  Worldwide 
   
  ■ Habitat  Lakes of the northern hemisphere 
   
  ■ Length  6 ft (1.8 m)
  Fabulous Lepidotes fossils have been found, with clear skin 
  impressions. Lepidotes had thick, diamond-shaped scales. 
  In life, this fish would have had a glossy appearance,  
  thanks to a hard coating over the scales that reflected light.
  Lepidotes
  leppy-DOE-tees
  u TEETH
  Looking like  
  little stones when 
  fossilized, Lepidotes’s 
  teeth were once known as 
  “toadstones” and were thought 
  to have magical properties. 
  EARLY VERTEBRATES
  542 million years ago
  4.6 billion years ago
  Precambrian Eon
  Cambrian
  Ordovician
  Silurian
  Devonian
  Carboniferous
  299
  359
  416
  444
  488
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  77
  Sucker lips
  Lepidotes had a trick when it came 
  to feeding. It could push out its 
  jaw, in the same way a carp does 
  today, and would then suck in 
  prey such as shellﬁsh. Shells 
  proved no barrier to this ﬁsh’s 
  hard, peglike teeth.
  Today’s carp are able to push forward their 
  jaws, just as Lepidotes once did.
  EARLY VERTEBRATES
  Our teeth and the teeth of 
  all vertebrates evolved 
  from the scales of 
  prehistoric ﬁsh. The scales 
  of Lepidotes were covered 
  in dentine and coated with 
  enamel, the same material 
  that makes up our teeth. Even 
  the structure of these scales  
  looks similar to human teeth. 
  DID YOU KNOW...?
  Permian
  Triassic
  Jurassic
  Cretaceous
  Paleogene
  Neogene
  251
  200
  145
  65
  23
  Now
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  78
  Lobe-ﬁnned ﬁsh
  Instead of using their ﬁns for steering, the members of this 
  ﬁsh family began using them to “walk” into crevices in reefs 
  and to push themselves along the seaﬂoor. As the years 
  passed, their ﬁns became stockier and muscular—they 
  were beginning to turn into legs. Called the “lobe-ﬁnned 
  ﬁsh,” these ﬁsh were the ﬁrst vertebrates to crawl out of 
  water and begin to live on land.
   
  ■ When  400 million years ago (Late Devonian) 
   
  ■ Fossil location  Latvia, Lithuania, Estonia, Russia 
   
  ■ Habitat  Oceans 
   
  ■ Length  5 ft (1.5 m) 
  Even though Panderichthys (right) was a 
  ﬁsh, it may have been able to climb on to  
  land, propping itself on its front ﬁns for just  
  a moment. It had ﬁns in pairs and scales all  
  over its body, like ﬁsh today. However, its ﬁns 
  were supported by bones similar to those of  
  an amphibian’s. It breathed through its gills 
  underwater, but an opening on top of its head, 
  probably connected to a lunglike air chamber, 
  allowed it to breathe on land as well. 
  Panderichthys
  PAN-der-ICK-thiss
   
  ■ When  Nearly 380 million years ago 
  (Late Devonian) 
   
  ■ Fossil location  Canada 
   
  ■ Habitat  Shallow seas 
   
  ■ Length  3 ft (1 m) 
  This strange creature (right) was like a 
  cross between a ﬁsh and a salamander.  
  It had a ﬂat head with eyes on top—
  perhaps for peeping above the water’s 
  surface—and a neck joint that allowed 
  it to turn its head. Its “ﬁns” had wrist 
  and shoulder joints and even simple 
  ﬁngers. Tiktaalik couldn’t truly walk, 
  but it could probably wriggle out of 
  water and use the ﬁns to prop itself up.
  Tiktaalik
  tik-TAA-lick
   
  ■ When  385 million years ago (Late Devonian)  
   
  ■ Fossil location  N. America, Greenland, Scotland, 
  Latvia, Estonia 
   
  ■ Habitat  Oceans 
   
  ■ Length  5 ft (1.5 m) 
  Eusthenopteron
  YOOS-then-OP-ter-on
  Key features
   
  ■ Stocky, rounded (lobe-shaped) fins 
  supported by bones
   
  ■ Gills to breathe in water
   
  ■ Some also had lunglike air chambers  
  to breathe air  
  When
  These fish appeared in the Ordovician 
  Period (505–440 million years ago). 
  Many died out at the end of the 
  Cretaceous Period, 65 million years ago, 
  but lobe-finned fish still exist today.
  u FISH OUT OF WATER
  Panderichthys was like an amphibian in some 
  ways. Although its body was long and slender, its 
  head was wide and ﬂattened with large eyes on 
  top, giving it a froglike face.
  Like most ﬁsh, Eusthenopteron was covered 
  in scales and had ﬁns. However, the bones 
  supporting its ﬁns were similar to those of  
  the ﬁrst amphibians (animals that live partly  
  in water and partly on land). A predator, 
  Eusthenopteron may have lurked in clumps 
  of seaweed, waiting to ambush passing prey. 
  FAMILY FACT FILE
  EARLY VERTEBRATES
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  79
   
  ■ When  370 million years ago (Late Devonian) 
   
  ■ Fossil location  Scotland, N. America 
   
  ■ Habitat  Rivers and lakes 
   
  ■ Length  14 in (35 cm) 
  Dipterus was a lungﬁsh and a close relative 
  of modern lungﬁsh (strange ﬁsh that can 
  breathe air and hibernate in burrows to survive 
  droughts). A large plate over its gill chamber 
  suggests Dipterus relied more on its gills than 
  lungs. It had tough teeth, perhaps to crack 
  shellﬁsh, and bony armor plates on its head.
  Dipterus
  DIP-ter-us
  In 1938, ﬁshermen in South Africa found  
  a strange ﬁsh in a shark net and showed  
  it to a local scientist. To everyone’s 
  astonishment, it turned out to be a 
  coelacanth (“SEE-la-canth”)—a type of ﬁsh 
  thought to have been extinct since the age 
  of dinosaurs. This “living fossil” was the 
  zoological ﬁnd of the century. 
  LIVING RELATIVE
   
  ■ When  390 million years ago (Devonian)
   
  ■ Fossil location  Scotland, Latvia, Lithuania, Estonia 
   
  ■ Habitat  Shallow lakes 
   
  ■ Length  20 in (50 cm) 
  Large, square scales on  
  its body gave Osteolepis 
  its name (meaning 
  “bony scale”). The 
  scales and the skull 
  bones were covered 
  with a glossy 
  substance rather  
  like the enamel of 
  human teeth. It lived 
  in the northern lakes 
  of Scotland in the 
  Devonian Period.
  Osteolepis
  OST-ee-oh-LEEP-iss
   
  ■ When  70 million years ago (Late Cretaceous)
   
  ■ Fossil location  England, Czech Republic 
   
  ■ Habitat  Oceans 
   
  ■ Length  22 in (55 cm)  
  Macropoma belonged to the family of ancient 
  ﬁsh known as coelacanths, which had ﬂeshy ﬁns 
  that they could move in a similar fashion to our 
  arms and legs. Coelacanths were once believed 
  to be an evolutionary link between ﬁsh and land 
  animals. However, scientists now think that they 
  were not the direct ancestors of land animals.
  Macropoma
  mack-roe-POME-ah
  EARLY VERTEBRATES
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  80
  Conquering land
  We know that land animals today evolved from creatures 
  that lived in water millions of years ago. To move onto 
  land, certain barriers had to be overcome—after all, a ﬁn 
  or ﬂipper is not much use on land. Let’s take a look at 
  some of the changes that took place. 
  Ichthyostega
  Tiktaalik
  Eusthenopteron
  Pectoral ﬁn
  Transitional 
  footlike structure
  Hind limb
  385 million years ago
  375 million years ago
  365 million years ago
  FROM FINS TO LEGS 
  Legs evolved from the ﬁns of ﬁsh. The ﬁrst animals to develop 
  legs—the tetrapods—had four legs with digits at the end of each 
  one. Some had up to eight digits.
  EARLY VERTEBRATES
  . PROTEROGYRINUS This 
  amphibian enjoyed a diet of ﬁsh, but 
  did not spend its life submerged in 
  water. It used lungs to breathe, and 
  was one of the ﬁrst animals to do so.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  81
  EARLY VERTEBRATES
  Breathing air
  Land animals take oxygen from air and have no need for 
  the gills that ﬁsh use to extract oxygen from water. Lungs 
  evolved in some early ﬁsh to help them gulp air at the 
  water’s surface. One group of ﬁsh retained lungs, which 
  were crucial when they began clambering onto land. 
  Among the ﬁrst ﬁsh to clamber onto land and breathe out 
  of water were the lungﬁsh, some 400 million years ago.
  u FIRST TRACKS These fossilized tracks were found in 2010 
  in Canada. They are around 318 million years old and are 
  believed to be evidence of some of the oldest reptiles.
  PROTECT THE YOUNG!
  One of the most important steps 
  in freeing animals from a 
  dependence on water was the 
  evolution of eggs that could be 
  laid on land. Most amphibians 
  have to return to water to breed, 
  but the ﬁrst reptiles had eggs with 
  lots of membranes, and later 
  shells, to help the egg withstand 
  dry conditions. 
  Prehistoric lungﬁsh were found  
  all over the world in the Devonian 
  Period, some 400 million years ago.
  u NO NEED FOR WATER 
  A tortoise’s eggs do not dry out due to 
  their shells and internal membranes.
  d ANCIENT Turtles 
  and tortoises date back 
  some 220 million years.
  u SURVIVAL Turtle and tortoise young spend 
  about 6–8 weeks in their egg. All the moisture 
  they need is contained inside the egg.
  Nearly all land-dwelling vertebrates have 
  ﬁve digits (ﬁngers or toes) in each foot, 
  and the same arrangement of bones in 
  each limb. That’s because they all evolved 
  from the same ancestor—one of the 
  early land pioneers, which happened  
  to have ﬁve-ﬁngered feet.
  A bit about digits
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  82
  Amphibians
  Amphibians are animals that spend their lives partly  
  in water and partly on land. They evolved from fish 
  about 370 million years ago as fins slowly turned into 
  fully formed legs that allowed them to walk on land. 
  Amphibians were the first four-legged animals (“tetrapods”) 
  and the ancestors of all four-legged animals alive today, 
  from frogs and mice to elephants and humans.
   
  ■ When  300 million years ago (Early Permian) 
   
  ■ Fossil location  Czech Republic 
   
  ■ Habitat  Swamps of eastern Europe
   
  ■ Length  Almost 6 in (15 cm) 
  Microbrachis (below) looked like a tiny 
  salamander with puny limbs. It had gills for 
  breathing in water and probably swam like a 
  fish, propelling itself forward by swishing its 
  flattened tail from side to side. It seems  
  to have spent most of its time in swamps, 
  rivers, lakes, and ponds, where it hunted  
  for prey such as small fish and shrimp.
  Microbrachis
  MY-crow-BRACK-iss
   
  ■ When  290 million 
  years ago (Early 
  Permian) 
   
  ■ Fossil location  
  USA, Germany 
   
  ■ Habitat  Swamps of 
  N. America and  
  western Europe 
   
  ■ Length  About 2 ft (60 cm) 
  For many years 
  Seymouria was 
  believed to have 
  been an early 
  reptile because it had sturdy legs and was  
  well suited to life on land. However, scientists 
  discovered that a close relative of Seymouria 
  had external gills in early life, like a tadpole, 
  which suggests Seymouria did too. Although 
  adults lived on land, youngsters probably  
  lived entirely in water. The adult males had 
  thick skulls that may have been used  
  to butt rivals in mating contests. 
  Seymouria
  see-MORE-ee-ah
   
  ■ When  300 million years ago (Late Carboniferous 
  to Early Permian) 
   
  ■ Fossil location  USA, Czech Republic 
   
  ■ Habitat  Swamps of N. America and western Europe 
   
  ■ Length  About 3 ft (0.9 m) 
  Phlegethontia belonged to a group of 
  amphibians that had evolved snakelike  
  bodies and lost their legs. It had rows of  
  small, spiked teeth similar to those found  
  in some nonvenomous snakes. 
  Phlegethontia
  FLEH-geh-THON-tee-ah
   
  ■ When  370 million years ago 
  (Late Devonian) 
   
  ■ Fossil location  Greenland 
   
  ■ Habitat  Shallow northern seas 
   
  ■ Length  About 5 ft (1.5 m) 
  Ichthyostega’s head, body, and 
  tail fin were like those of a 
  fish, but it had webbed feet 
  like a frog’s. It used lungs to 
  breathe on land and had strong 
  shoulder muscles that supported  
  its weight out of water and helped  
  it to crawl around. It hunted for fish  
  and other prey in shallow pools.
  Ichthyostega
  ICK-thee-oh-STAY-gah 
  Fossilized foot
  EARLY VERTEBRATES
  Microbrachis
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  83
   
  ■ When  295 million years ago (Early Permian) 
   
  ■ Fossil location  N. America 
   
  ■ Habitat  Swamps of N. America and western Europe 
   
  ■ Length  About 6 ft (1.8 m) 
  One of the largest land animals  
  of its time, Eryops looked like a 
  fat crocodile. It had a long 
  snout (its name means 
  “drawn-out face”), and 
  Eryops
  EH-ree-ops
   
  ■ When  350 million years ago (Early Carboniferous) 
   
  ■ Fossil location  Scotland and USA 
   
  ■ Habitat  Shallow waters of northern Europe 
   
  ■ Length  About 5 ft (1.5 m) 
  This bizarre creature probably lived in water,  
  since its tiny limbs would have made walking 
  on land impossible. It was a large and powerful 
  predator, with two rows of sharp teeth lining a 
  huge mouth that it used to catch prey with  
  a snapping motion. Large eyes suggest it  
  could have hunted well in murky water,  
  or perhaps at night.
  Crassigyrinus
  CRASS-ee-jih-RYE-nuss
  Key features
   
  ■ Four limbs with wrist and elbow joints
   
  ■ Distinct fingers and toes
   
  ■ Eggs laid in water
   
  ■ Fishlike larvae (babies)
  When
  Amphibians evolved from fish during  
  the Devonian Period, 370–400 million 
  years ago.
  its huge, strong jaws were lined with sharp 
  fangs. It couldn’t chew and so would have 
  ﬂung its head up and backward, tossing prey  
  further into its mouth just as crocodiles  
  and alligators do today. Eryops had sturdy 
  limbs but moved slowly on land because  
  of its bulky body and short legs.
   
  ■ When  365 million years ago (Late Devonian) 
   
  ■ Fossil location  Greenland 
   
  ■ Habitat  Northern rivers and swamps 
   
  ■ Length  About 2 ft (0.6 m) 
  This is believed to 
  have been the 
  ﬁrst tetrapod 
  capable of 
  brieﬂy climbing 
  out of water. It had lungs but also 
  gills and is thought to have lived largely in 
  shallow swamps. Unlike its ﬁsh relatives, 
  Acanthostega had eight webbed 
  digits on its forelimbs. 
  Acanthostega
  ah-CAN-tho-STAY-gah
  EARLY VERTEBRATES
  FAMILY FACT FILE
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  84
  Amphibamus
  Lush tropical forests and swamps covered the 
  land in the Late Carboniferous Period. Giant 
  insects buzzed around, and the newly evolved 
  amphibians chased after them (see previous 
  page). Some were as big as alligators, but tiny 
  Amphibamus was the size of a newt. It had 
  many of the features of modern frogs and 
  salamanders and may have 
  been their ancestor.
  u SKELETON 
  More than 350 million years old, this fossil  
  of Amphibamus was found in Ohio. 
  The wide head and large eye sockets 
  are clearly visible. 
  EARLY VERTEBRATES
  SKIN BREATHER 
  Amphibamus fossils come from a site that 
  was a river delta in the Carboniferous Period. 
  Perhaps the animal lived in creeks or swamps 
  near the river. Like most amphibians it might 
  have been able to breathe through its moist 
  skin, but it would have had to stay in damp 
  places so its skin didn’t dry out. 
   
  ■ When  300 million years ago (Late Carboniferous) 
   
  ■ Fossil location  USA 
   
  ■ Habitat  Swamps of N. America and 
  western Europe 
   
  ■ Length  6 in (15 cm)
   
  ■ Diet  Probably insects
  Amphibamus had large eyes for spotting 
  prey. Perhaps it hunted by standing still and 
  snatching insects that came close, as frogs do. 
  Like most modern amphibians, it may have 
  had to return to water to breed and lay eggs.
  Amphibamus
  AM-fee-bah-muss
  Precambrian Eon
  Cambrian
  Ordovician
  Silurian
  Devonian
  416
  444
  488
  542 million years ago
  4.6 billion years ago
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  85
  Salamanders are related to frogs but have long, slender bodies. They 
  live in damp places and can breathe through their moist skin. Some 
  species lay their eggs in water, the eggs hatching out into tadpoles 
  that breathe through gills. Others species breed entirely on land.
  LIVING RELATIVE
  EARLY VERTEBRATES
  Carboniferous
  Permian
  Triassic
  Jurassic
  Cretaceous
  Paleogene
  Neogene
  251
  299
  359
  200
  145
  65
  23
  Now
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  86
  EARLY VERTEBRATES
  Early plants
  Plants can be divided into spore-producing 
  plants, such as mosses and ferns, and 
  seed-bearing plants, such as ﬂowering plants. 
  There are now thought to be more than 
  400,000 identiﬁed species. But where  
  did they ﬁrst come from? 
  The beginnings
  Plants originated as algae—
  simple organisms that live 
  in water and feed oﬀ the 
  Sun’s energy. The ﬁrst algae 
  lived in the sea. Over time, 
  they spread into fresh water 
  habitats and into damp 
  places on land. 
  An unusual “seed”
  Plants such as mosses and ferns have 
  capsules that hold spores. Spores are 
  a bit like seeds, but microscopic and 
  not as hardy. Spores were a good 
  means for early plants to reproduce, 
  because an organism can produce 
  millions of spores.
  Moving onto land
  More than 400 million years 
  ago, plants started to grow 
  on land. The ﬁrst land 
  plants were small, mosslike 
  organisms and had no true 
  leaves, roots, or ﬂowers.
  With the spread of 
  plants, more oxygen 
  was released into the 
  atmosphere. Plants 
  were changing the 
  planet.
  Spore-producing plants need damp 
  conditions in which to reproduce.
  Plantlike organisms ﬂourished 
  420–370 million years ago. Long 
  before the reign of the dinosaurs, 
  Prototaxites like these could 
  reach 26 ft (8 m) in height.  
  It’s possible these were fungi 
  rather than plants.
  Aglaphyton collected 
  light with its entire 
  surface. Spore-producing, 
  egg-shaped capsules grew 
  on its tips.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  87
  d WILLIAMSONIA These stocky trees 
  would have been familiar to Jurassic and 
  Cretaceous dinosaurs throughout the 
  world. This plant had ﬂowerlike parts. 
  Learn more about the emergence of 
  ﬂowers on pages 224–225.
  EARLY VERTEBRATES
  Conifer forests
  During the dinosaur era, 
  forests were dominated by 
  towering conifer trees. These 
  have thin, needlelike leaves, 
  which cope well with hot, 
  dry climates. The monkey 
  puzzle tree is a type of 
  conifer that still survives 
  from this period.
  A helping hand
  As forests ﬂourished, plants 
  began to compete to reach 
  the light. Woody stems 
  evolved, allowing plants to 
  reach higher. Plants similar 
  to those we know today 
  began to appear. Tree ferns, 
  for instance, would have 
  been familiar to the 
  dinosaurs.
  Early seeds
  This plant may look as if  
  it’s producing fruits, but 
  actually it is bearing seeds, 
  each the size of an egg. 
  Medullosa was the size of 
  a small tree. It appeared 
  about 350 million years ago.
  Land plants spread out
  When plants such as Cooksonia evolved sturdier stems, plants began 
  to grow taller and spread farther across land. Later, plants evolved 
  the ability to produce seeds, which can sprout in much drier places 
  than spores. Dense forests then sprang up, turning the land green.
  Cooksonia, one of the ﬁrst upright 
  plants, appeared 425 million years ago. 
  It was just 4 in (10 cm) tall and could 
  support itself with branching stems.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  90
  EARLY VERTEBRATES
  Effigia
  It looked like a dinosaur, ran like a dinosaur, and 
  probably fed like a dinosaur, too—but Effigia was 
  no dinosaur. This Triassic reptile belonged to the  
  same part of the reptile family tree as crocodiles and 
  alligators but evolved a body shape remarkably similar 
  to that of the ostrich dinosaurs (ornithomimids), 
  which were not to appear until 80 million years later.
   
  ■ When  210 million years ago (Late Triassic) 
   
  ■ Fossil location  USA 
   
  ■ Habitat  Woodlands of western N. America 
   
  ■ Length  5–10 ft (1.5–3 m) 
   
  ■ Diet  Unknown but possibly omnivorous
  Effigia walked on its hind legs, holding up its 
  long tail for balance, and had very tiny arms.  
  It had large eyes and a small, birdlike skull. 
  Reptiles like Effigia were common in the 
  Late Triassic but seem to have been killed by a 
  change in climate caused by volcanic eruptions.  
  Effigia
  eff-IJ-ee-ah
  u WHO NEEDS TEETH?
  Effigia had a beak but no teeth, which 
  makes its diet hard to guess. Perhaps it 
  used its beak to crack pine seeds or eggs.  
  It may also have preyed on small animals. 
  Modern pine cones
  542 million years ago
  4.6 billion years ago
  Precambrian Eon
  Cambrian
  Ordovician
  Silurian
  Devonian
  Carboniferous
  299
  359
  416
  444
  488
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  91
  EARLY VERTEBRATES
  u LIKE A DINOSAUR 
  Effigia shared many features 
  with dinosaurs, from large 
  eyes and small arms to a 
  toothless beak. Its ankles, 
  however, were much more 
  like those of a crocodile.
  Toothless beak
  Crocodile-like ankle
  Long neck
  Small arms
  Long hind legs
  Long tail
  DID YOU KNOW...?
  Efﬁgia (which means “ghost” in Greek) 
  was named after the Ghost Ranch Quarry  
  in New Mexico, where its fossil was 
  found in 1947. Efﬁgia has lived up to its 
  name—the fossil lay hidden from sight for 
  nearly 60 years, trapped inside an unopened 
  slab of rock in an American museum. That 
  is, until 2006, when the rock was cracked 
  open and Efﬁgia was discovered.
  Permian
  Triassic
  Jurassic
  Cretaceous
  Paleogene
  Neogene
  251
  200
  145
  65
  23
  Now
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  92
  EARLY VERTEBRATES
  Crocodylomorphs
  Crocodylomorphs (which means having a crocodile-like 
  shape) were part of the archosaur, or “ruling reptile” 
  group, along with dinosaurs and pterosaurs. Some 
  were small, others gigantic, and they lived both on 
  land and in the sea. Like their modern relatives— 
  crocodiles and alligators—most were active hunters, 
  always ready to ambush passing fish or land animals. 
   
  ■ When  200 million years ago (Early Jurassic) 
   
  ■ Fossil location  S. Africa
   
  ■ Habita  Land 
   
  ■ Length  3–5 ft (1–1.5 m)
   
  ■ Diet  Small land animals
  Sphenosuchus was one of the earlier 
  crocodylomorphs. It had long and slender  
  legs—a sign it could run fast when chasing 
  prey or fleeing from predators. Only a  
  skull and a few leg bones have been found. 
  Air-filled spaces in parts of the skull resemble 
  those found in birds, hinting at an evolutionary 
  link between crocodylomorphs and birds.
   
  ■ When  165–140 million years ago 
  (Late Jurassic to Early Cretaceous) 
   
  ■ Fossil location  Europe, N. America, the Caribbean
   
  ■ Habitat  Oceans
   
  ■ Length  10 ft (3 m)
   
  ■ Diet  Fish
  When scientists first came across fossils of  
  this species they thought it lived on land, and 
  gave it the name Geosaurus, or “earth lizard.” 
  They now know that this animal spent most  
  of its life underwater. Geosaurus had a 
  much longer and narrower snout than most 
  crocodylomorphs. It may also have had a  
  special gland in its mouth, like crocodiles 
  and gharials, to help it 
  remove salt from the 
  water it drank.
  Sphenosuchus
  SFEN-oh-soo-kuss
  Geosaurus
  GEE-oh-SORE-us
  FAMILY FACT FILE
  Key features
   
  ■ Long bodies
   
  ■ Short, strong limbs
   
  ■ Powerful jaws
   
  ■ Sharp teeth
  When
  Crocodylomorphs first appeared 225 
  million years ago, in the Late Triassic  
  and were the ancestors of modern 
  crocodiles and alligators. 
  Platelike scales 
  made of bone
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  93
  EARLY VERTEBRATES
   
  ■ When  200–145 million years ago 
  (Early Jurassic to Early Cretaceous)
   
  ■ Fossil location  Europe, Africa
   
  ■ Habitat  Estuaries and coastal waters
   
  ■ Length  3–13 ft (1–4 m)
   
  ■ Diet  Fish
  Steneosaurus was probably an estuary-living 
  crocodylomorph that ventured out onto  
  land to lay its eggs. Although its long body 
  was adapted for swimming, its limbs had  
  not changed into flippers. It had a thin snout 
  full of sharp teeth for eating fish, and its  
  body was heavily armored to protect  
  it against predators.
   
  ■ When  70–65 million years ago (Late Cretaceous) 
   
  ■ Fossil  location USA, Mexico
   
  ■ Habitat  Swamps
   
  ■ Length  33 ft (10 m)
   
  ■ Diet  Fish, medium to large dinosaurs
  Deinosuchus was one of the largest prehistoric 
  alligators, nearly five times bigger and heavier 
  than any found today. This alligator may have 
  Steneosaurus
  STEN-ee-oh-SORE-us
   
  ■ When  165–140 million years ago 
  (Late Jurassic to Early Cretaceous) 
   
  ■ Fossil location  Worldwide
   
  ■ Habitat  Shallow seas
   
  ■ Length  15 ft (4–5 m)
   
  ■ Diet  Fish, squid, and marine reptiles
  Dakosaurus was a fierce marine predator. With a skull 
  like that of a carnivorous dinosaur and large, jagged 
  teeth, it had a powerful bite that could slice through the 
  flesh of other marine reptiles and crunch the shells of ammonites. Its legs  
  had become paddles that helped it steer as its fishlike tail propelled it through 
  the water. It could chase and overcome animals much bigger than itself. 
   
  ■ When  70 million years ago (Late Cretaceous) 
   
  ■ Fossil location  Madagascar
   
  ■ Habitat  Forests
   
  ■ Length  4 ft (1.2 m)
   
  ■ Diet  Plants, maybe some insects
  Simosuchus was an unusual crocodylomorph 
  because it had a short skull and blunt face. In 
  fact, its name means “pug-nosed 
  Dakosaurus
  DACK-oh-SORE-us
  Simosuchus
  SIGH-moe-SOO-kuss
  Deinosuchus
  DIE-no-SOO-kuss
  crocodile.” Even more unusually, this  
  reptile’s teeth show that it was probably  
  a vegetarian that occasionally ate insects.  
  New research suggests that its tail may  
  have been much shorter than that shown  
  in the illustration below.
  Tooth sockets
  u UNDERWATER TERROR
  Deinosuchus killed its prey as 
  modern alligators do—by 
  dragging its victims underwater 
  and drowning them. 
  Long, powerful jaws 
  with large, sharp teeth
  preyed on dinosaurs as big as itself—fossils  
  of certain tyrannosaurs show Deinosuchus 
  bite marks. It may have hunted by waiting 
  patiently at the water’s edge to pounce on 
  passing fish, marine reptiles, or land animals. 
  Small victims were swallowed whole. Larger 
  prey were ripped apart into bite-sized chunks.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  94
  Pterosaurs
  The skies above the dinosaurs were 
  alive with ﬂying reptiles. These 
  were the pterosaurs. They were  
  not dinosaurs, but they were  
  close relatives. One of the largest 
  pterosaurs was Quetzalcoatlus. 
  This colossal animal was easily 
  the size of a fully grown 
  giraﬀe—but with a wingspan 
  that would have stretched 
  across a tennis court.
  FAMILY FACT FILE
  Key features
  ■  Each wing formed from skin stretched 
  between an extra-long finger and the leg. 
  ■  Some pterosaurs had head crests. 
   
  ■ Large eyes 
  ■  Long, narrow jaws
  ■  Hollow bones
  ■  Pterosaurs flapped their wings
   
  When
  Pterosaurs first appeared in the late 
  Triassic, 215 million years ago, and 
  survived until the end of the Cretaceous 
  Period, 65 million years ago.
   
  ■ When 70–65 million years ago 
  (Cretaceous)
   
  ■ Fossil location  USA  
   
  ■ Habitat  Plains and woodlands  
   
  ■ Size  33–36 ft (10–11 m) wingspan    
  This pterosaur had a larger wingspan than 
  a small plane, yet light bones meant that 
  it only weighed around 550 lb (250 kg). 
  During the day it soared over great 
  distances, looking for small or baby 
  dinosaurs to snap up in its giant, 
  toothless jaws. It was one of the largest 
  ﬂying animals of all time.
  Quetzalcoatlus
  KWETSul-coe-AT-luss
  EARLY VERTEBRATES
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  95
  d WINGS A pterosaur’s wing 
  was made of skin stretched 
  between an extremely long 
  ﬁnger bone and the leg.
  Rhamphorhynchus 
  ram-foe-RINK-us
   
  ■ When  150 million years ago (Jurassic)
   
  ■ Fossil location  Europe, Africa 
   
  ■ Habitat  Coastal and riverside
   
  ■ Size  16 in (40 cm) long  
  With its slim, spiked teeth, throat pouch, and 
  long, narrow jaw, Rhamphorynchus was 
  perfectly adapted for the coastal environment 
  in which it lived. Its long tail had a diamond-
  shaped ﬂap of skin at the end and was perhaps 
  used to help this pterosaur steer.
  . PTERANODON probably ﬂew like 
  an albatross, using its huge wings to soar 
  and ﬂapping them only occasionally.
  Pteranodon
  teh-RAN-oh-don
   
  ■ When  88–80 million years ago (Cretaceous)
   
  ■ Fossil location  North America 
   
  ■ Habitat Coastal 
   
  ■ Size  23–30 ft (7–9 m) wingspan  
  This creature’s name means “wings and no 
  teeth.” It was one of the largest pterosaurs. 
  Pteranodons lived in huge ﬂocks and cruised 
  over the ocean looking for ﬁsh to scoop up in 
  their slender, pointed beaks. A large head crest 
  may have been used for display.
   
  ■ When  200–180 million years ago (Jurassic)
   
  ■ Fossil location British Isles 
   
  ■ Habitat Coastal woodlands 
   
  ■ Size  24 in (60 cm) long  
  Dimorphodon’s head was almost a third of 
  its body length and contained two types of 
  teeth, which was unusual for a pterosaur. (Its 
  name actually means 
  “two-form tooth.”) 
  It probably 
  hunted small 
  vertebrates, such 
  as lizardlike reptiles, snapping 
  its jaws closed with immense 
  speed to trap them.
  Dimorphodon
  die-MORE-foe-don
   
  ■ When  150–144 million years ago (Jurassic)
   
  ■ Fossil location  Germany 
   
  ■ Habitat Coastal
   
  ■ Size  12 in (30 cm) long  
  Many complete skeleton ﬁnds have ensured 
  that Pterodactylus has become one of the best 
  known of pterosaurs. This animal had a very 
  short tail and a longer neck than earlier 
  pterosaurs, making it a better ﬂyer. 
  Pterodactylus
  TEH-roe-DACK-till-us
  u PTERODACTYLUS This 
  fossil discovered in Germany is 
  one of the most complete and best-
  preserved pterosaur fossils known.
  EARLY VERTEBRATES
  Pterodactylus
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  96
  Eudimorphodon
  Gliding on its leathery wings, Eudimorphodon was one 
  of the first pterosaurs to take to the skies. Its front limbs 
  had grown very long, its fourth fingers had stretched  
  out, and together they formed the front edges of a pair  
  of wings. Thin membranes of skin and muscle stretched 
  back toward its hind legs. Powered by strong chest and 
  arm muscles, these reptiles became masters of the air.
  EARLY VERTEBRATES
  TOOTHY FISH-EATER
  Eudimorphodon had more than 100 teeth 
  packed into a jaw that was as short as a  
  human finger. The front teeth were like fangs 
  and faced outward, making it easier to catch 
  slippery fish. The rear teeth had many little 
  points, like human cheek teeth, that helped 
  Eudimorphodon to chew its food.
  542 million years ago
  4.6 billion years ago
  Precambrian Eon
  Cambrian
  Ordovician
  Silurian
  Devonian
  Carboniferous
  299
  359
  416
  444
  488
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  97
   
  ■ When  210 million years ago (Late Triassic) 
   
  ■ Fossil location  Italy, Greenland
   
  ■ Habitat  Coasts
   
  ■ Length  3 ft (1 m)
   
  ■ Diet  Fish
  This small reptile is one of the earliest 
  pterosaurs. It had a long tail and a short  
  neck, features that were lost in later species  
  of pterosaur. Eudimorphodon glided through the 
  skies, snatching fish near the surface of the water 
  and probably insects, too. A diamond-shaped 
  flap at the end of its bony tail helped it  
  to steer while in flight. 
  Eudimorphodon
  YOU-die-MORE-fo-don
  EARLY VERTEBRATES
  Sharp, pointed 
  teeth were good  
  for spearing fish.
  The body and wings were 
  covered in a hairy fuzz that 
  helped Eudimorphodon to 
  keep warm.
  Permian
  Triassic
  Jurassic
  Cretaceous
  Paleogene
  Neogene
  251
  200
  145
  65
  23
  Now
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  98
  Nothosaurs
  In the middle of the Triassic, when the ﬁrst dinosaurs were 
  beginning to walk on land, the seas were home to a family of 
  reptiles known as nothosaurs. A bit like today’s seals and sea 
  lions, the nothosaurs were ﬁsh hunters that evolved 
  from land animals. They weren’t fully adapted 
  to life in water and some had 
  clawed feet—a sign they 
  could still walk on land.
  Pachypleurosaurus
  PACK-ee-ploo-roe-SORE-us
  EARLY VERTEBRATES
  u STREAMLINED 
  With its legs ﬂat against the 
  body, Pachypleurosaurus had 
  a streamlined, almost snakelike 
  shape. It could dart quickly  
  through the water, powered by  
  a long and muscular tail.
   
  ■ When  225 million years ago (Middle Triassic) 
   
  ■ Fossil location  Italy, Switzerland 
   
  ■ Habitat  Oceans 
   
  ■ Length  12–16 in (30–40 cm) 
   
  ■ Diet  Fish
  Pachypleurosaurus is sometimes classiﬁed 
  as a nothosaur and sometimes as a member  
  of a separate but closely related family 
  (pachypleurosaurs). It was a small animal  
  with a long, slender body and a long neck and 
  tail. It swam by moving its body in a wavelike 
  pattern, using paddlelike limbs for steering and 
  balance. Most of its fossils have been discovered 
  in rocks formed from marine sediments.
  Webbed foot
  Cambrian
  Ordovician
  Silurian
  Devonian
  Carboniferous
  Permian
  299
  359
  416
  488
  444
  542 million years ago
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  99
  EARLY VERTEBRATES
  , SWIMMING Nothosaurus probably 
  swam like an otter, waving its long, powerful 
  tail to drive itself through the water. The 
  webbed feet were better suited to  
  walking on land than swimming,  
  but they may have helped 
  Nothosaurus make sharp 
  twists and turns as it 
  chased its prey.
   
  ■ When  240–210 million years ago 
  (Early to Late Triassic) 
   
  ■ Fossil location  Europe, N. Africa, Russia, China 
   
  ■ Habitat  Oceans 
   
  ■ Length  4–13 ft (1.2–4 m) 
   
  ■ Diet  Fish
  Like a seal, Nothosaurus hunted in the 
  water but probably came ashore to rest.  
  It had amazingly long and needle-sharp teeth 
  to seize ﬁsh. The teeth interlocked to form a 
  cage, trapping prey in the mouth. Nothosaurus 
  had a long and muscular neck. Some experts 
  think it could twist its head sideways like  
  a crocodile to grab passing ﬁsh—a trick 
  known as “snap feeding.”
  Nothosaurus
  NO-tho-SORE-us
  Now
  Triassic
  Jurassic
  Cretaceous
  Paleogene
  Neogene
  251
  200
  145
  65
  23
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  100
  EARLY VERTEBRATES
  Plesiosaurs
  During the Jurassic and Cretaceous periods, when 
  dinosaurs ruled the land, the oceans were ruled by 
  gigantic carnivorous reptiles called plesiosaurs. There 
  were two main types: long-necked plesiosaurs, which 
  had long, snakelike necks and small, dainty heads; 
  and short-necked plesiosaurs (pliosaurs), which  
  had huge heads and enormous, fang-ﬁlled jaws.
  Ribs in the middle 
  of the trunk
  Small head
  Jaw
  Short, tapered tail
  Sharp, pointed 
  teeth
  Paddlelike ﬂipper
   
  ■ When  200 million years ago (Early Jurassic)
   
  ■ Fossil location  British Isles, Germany 
   
  ■ Habitat  Oceans 
   
  ■ Length  10–15 ft (3–5 m) 
   
  ■ Diet  Fish, squidlike mollusks 
  Plesiosaurus was a long-necked aquatic reptile 
  with a wide, turtlelike body. Like a turtle, it 
   
  ■ When  99–65 million years ago (Late Cretaceous) 
   
  ■ Fossil location  USA 
   
  ■ Habitat  Oceans 
   
  ■ Length  45 ft (14 m) 
   
  ■ Diet  Fish, squid, shellﬁsh 
  Elasmosaurus’s neck was as long as the rest of its 
  body. After its discovery in 1868, the ﬁrst scientists 
  to study this animal thought the long neck was its 
  tail and so put the head at the wrong end. This 
  long neck came in handy—as Elasmosaurus 
  swam slowly over the seabed, it  
  would reach down to pick prey 
  oﬀ the bottom.
  u EXPERTS ARGUE over how ﬂexible the long neck 
  of Elasmosaurus was. Some think it was as ﬂexible as a 
  snake’s body and could be coiled up or held right out of 
  the water. Others think it was stiﬀer but with enough 
  ﬂexibility to bend down and reach far to each side.
  FAMILY FACT FILE
  Plesiosaurus
  PLEE-see-oh-SORE-us
  Elasmosaurus
  el-LAZZ-moe-SORE-us
  Key features
   
  ■ Plesiosaurs had long necks and small 
  skulls; pliosaurs were short-necked,  
  with enormous skulls 
   
  ■ Four large flippers 
   
  ■ Many pointed teeth 
   
  When
  Plesiosaurs appeared in the Early Jurassic, 
  200 million years ago. They died out at 
  the end of the Cretaceous Period, 65 
  million years ago. 
  pushed itself through the water using its 
  ﬂippers, as the tail was too short to be of 
  much use. It hunted by swimming among 
  shoals of ﬁsh, swinging its long neck from  
  iside to side to snatch its prey. Plesiosaurus 
  had U-shaped jaws, which it could open  
  wide, trapping prey with its conical teeth.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  EARLY VERTEBRATES
   
  ■ When  165–150 million years ago (Mid to Late Jurassic) 
   
  ■ Fossil location  British Isles, France, Russia, Germany 
   
  ■ Habitat  Oceans 
   
  ■ Length  16–23 ft (5–7 m) 
   
  ■ Diet  Large squid, ichthyosaurs 
  One of the most powerful carnivores of all time, Liopleurodon had 
  massive jaws and probably a stronger bite than Tyrannosaurus. It 
  could easily have held a medium-sized car in its mouth and bitten 
  it in half. Scientists believe it had a strong sense of smell, which 
  helped it to hunt in deeper waters where prey was difficult to spot. 
   
  ■ When  65 million years ago (Late Cretaceous) 
   
  ■ Fossil location  Australia, Colombia 
   
  ■ Habitat  Oceans 
   
  ■ Length  33 ft (10 m) 
   
  ■ Diet  Marine reptiles, ﬁsh, mollusks
  Kronosaurus was one of the largest sea reptiles. 
  Even its head, at almost 10 ft (3 m) long, was 
  bigger than a man. This monster could open  
  its jaws wide like a crocodile and grasp prey  
  with teeth as big as bananas. Fossilized stomach 
  remains show that it ate other marine reptiles, 
  including other plesiosaurs. Like all plesiosaurs, 
  it had to rise to the surface to breathe air.
  Liopleurodon
  LIE-oh-PLOOR-oh-don
  Kronosaurus
  crow-no-SORE-us
  Each of the bones in 
  Liopleurodon’s spine was 
  the size of a dinner plate. 
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  102
  EARLY VERTEBRATES
  The Loch Ness monster
  Does a plesiosaur survive to this day? There have long been stories 
  of a mysterious prehistoric monster living in Loch Ness, a huge  
  lake in Scotland. Scientiﬁc evidence that “Nessie,” as the monster  
  is more familiarly known, exists has never been found, but many 
  people believe they have seen it and a few claim to have 
  photographed it. Could there be any truth in the rumors?
  EXCLUSIVE REPORT!
  The famous photo below was ﬁrst 
  published in an English newspaper  
  in 1934. It was said to be the ﬁrst 
  photo of the Loch Ness monster, and 
  it caused a great deal of excitement. 
  However, in 1994 the monster was 
  revealed as a fake, made from a toy 
  submarine attached to a neck and 
  head sculpted from wood ﬁller.
  u THE FAMOUS SHOT of “Nessie” is called 
  the “surgeon’s photograph” because it was supposedly 
  taken by a London doctor, Robert K. Wilson.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  103
  EARLY VERTEBRATES
  WHY A PLESIOSAUR?
  Pictures such as the surgeon’s photograph 
  show a long-necked creature like a 
  plesiosaur. They inspired theories that 
  Loch Ness’s hidden depths might harbor 
  creatures that survived from the age of the 
  dinosaurs. But the water is probably too 
  cold for giant reptiles, and Loch Ness was 
  frozen solid during the last ice age.
  , FOSSILIZED PLESIOSAUR 
  SKELETON Plesiosaurs had long 
  necks and small heads, just like images 
  of the Loch Ness monster. But their 
  necks were probably too weak to raise 
  the head high above the surface.
  u LOCH NESS is a 23-mile- (37-km-) long 
  lake in Scotland. Despite its size, scientists think 
  there are not enough ﬁsh in the lake to support  
  a predator the size of the Loch Ness monster.
  Computer generated 
  artwork of the Loch 
  Ness monster.
  Plesiosaur fossil
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  104
  EARLY VERTEBRATES
  Rhomaleosaurus
  In 1848, miners in a quarry in Yorkshire, England, were 
  astonished when they discovered the skeleton of a huge 
  creature buried in the rock. It was Rhomaleosaurus, one 
  of the most fearsome predators of the Jurassic seas.  
  At the time, the seas were ruled by two kinds of marine 
  reptile—the dolphinlike ichthyosaurs and lizardlike 
  creatures with long necks known as plesiosaurs. 
  Rhomaleosaurus belonged to the plesiosaur family. 
  Precambrian Eon
  Cambrian
  Ordovician
  Silurian
  Devonian
  Carboniferous
  Permian
  251
  299
  359
  416
  444
  488
  542 million years ago
  4.6 billion years ago
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  105
  EARLY VERTEBRATES
  . FLIPPER 
  Rhomaleosaurus swam 
  by beating its four powerful 
  ﬂippers, using them like wings to  
  “ﬂy” through the water in the same way 
  as penguins move underwater today. 
   
  ■ When  200–195 million years ago (Early Jurassic)
   
  ■ Fossil location  England, Germany 
   
  ■ Habitat  Coastal waters 
   
  ■ Length  15–21 ft (5–7 m) 
   
  ■ Diet  Fish, squid, and ocean reptiles 
  Rhomaleosaurus
  ROME-alley-oh-SORE-us
  Rhomaleosaurus was a pliosaur—a type of 
  plesiosaur with a short neck. It hunted by 
  sight and smell, perhaps allowing seawater  
  to ﬂow through its mouth and out of its 
  nostrils so it could pick up the scent of prey. 
  Fossilized remains of food in the bellies  
  of pliosaurs reveal that their diet included 
  squid, ﬁsh, and other plesiosaurs. 
  KILLER GRIP 
  Rhomaleosaurus used its cone-shaped 
  fangs to attack large prey. Like a 
  crocodile, it may have twisted its 
  victims around violently to tear  
  their bodies apart and make  
  them easier to swallow.
  CAMOUFLAGE 
  Like large sea animals today, 
  Rhomaleosaurus may have had a 
  pale belly and a dark back. This 
  pattern, known as countershading, 
  is a type of camouﬂage—it makes 
  marine animals harder to see both 
  from above and below.
  Triassic
  Jurassic
  Cretaceous
  Paleogene
  Neogene
  200
  145
  65
  23
  Now
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  EARLY VERTEBRATES
  Ichthyosaurs
  The ichthyosaurs were the largest sea-dwelling reptiles 
  of all time. They evolved from land-living reptiles that 
  adapted so well to life in the sea that some species 
  came to resemble dolphins. Like dolphins, they fed, 
  bred, and gave birth in water but had to return to  
  the surface to breathe air.
   
  ■ When  225–208 million years ago (Late Triassic) 
   
  ■ Fossil location  N. America 
   
  ■ Habitat  Oceans 
   
  ■ Length  Up to 70 ft (20 m) 
   
  ■ Diet  Fish, squid 
  Shonisaurus was like a cross between a 
  whale and a dolphin, with an enormous  
  body but a long, slender snout. Giant eyes 
  and toothlessness in adults suggest it was a 
  deep-diving squid hunter. One whale-sized 
  specimen found in Canada was 70 ft (20 m) 
  long—the largest marine reptile ever found. 
  FAMILY FACT FILE
  Shonisaurus
  SHON-ee-sore-us
  Key features
   
  ■ Large eyes for good underwater vision 
   
  ■ Flippers for steering and balance
   
  ■ Vertical tail fin
   
  ■ Gave birth to live babies rather than 
  laying eggs
   
  ■ Lungs for breathing air
  When
  Ichthyosaurs lived from about 245 million 
  years ago (Triassic Period) to nearly  
  90 million years ago (Cretaceous Period).
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  107
  EARLY VERTEBRATES
   
  ■ When  190 million years ago (Early Jurassic) 
   
  ■ Fossil location British Isles, Belgium, Germany
   
  ■ Habitat  Oceans 
   
  ■ Length  6 ft (1.8 m) long 
   
  ■ Diet  Fish 
  Ichthyosaurus was a small, slim-snouted ichthyosaur. It had 
  dozens of sharp, needlelike teeth and used them to catch  
  squid or other kinds of mollusks. Studies of the ear bones of 
  Ichthyosaurus show that it didn’t have the highly sensitive 
  hearing that dolphins have and couldn’t detect objects in  
  the water by using echoes (echolocation).
   
  ■ When  165–150 million years ago (Late Jurassic) 
   
  ■ Fossil location  Europe, N. America, 
  Argentina 
   
  ■ Habitat  Oceans 
   
  ■ Length  16 ft (5 m) 
   
  ■ Diet  Fish, squid, 
  mollusks 
   
  ■ When  230 million years ago (Middle Triassic) 
   
  ■ Fossil location  N. America, Europe, Asia
   
  ■ Habitat  Oceans 
   
  ■ Length  Up to 3 ft 3 in (1 m) 
   
  ■ Diet  Fish 
  Mixosaurus was one of the smallest ichthyosaurs. It swam by 
  beating its tail from side to side, perhaps using bursts of speed  
  to take shoals of fish by surprise. It caught prey in a long, narrow 
  snout, which was lined with sharp teeth. Fossils of Mixosaurus 
  have been found all over the world, indicating that the species  
  lived throughout the oceans.
  Ichthyosaurus
  ICK-thee-oh-SORE-uss
  Ophthalmosaurus
  off-THAL-mo-SORE-uss
  Mixosaurus
  MIX-oh-SORE uss 
  Tail fin
  Ophthalmosaurus 
  means “eye 
  lizard.” This ichthyosaur 
  had the largest eyes relative to body size of any prehistoric animal.  
  The eyes were as big as grapefruits and almost filled the skull. 
  Ophthalmosaurus could probably see well in the dark and may 
  have used its extraordinary vision to hunt in the depths of the  
  sea. If so, it must also have been good at holding its breath for  
  long periods on its trips into the deep.
  Eye socket
  Flat, broad paddle
  Rounded, 
  streamlined shape
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  108
  EARLY VERTEBRATES
  Stenopterygius
  Long before dolphins ﬁrst appeared, the seas of the Jurassic were 
  home to reptiles that had evolved a remarkably similar body 
  shape and lifestyle. These were the ichthyosaurs. One type of 
  ichthyosaur, Stenopterygius, spent its life in the open ocean, 
  where it hunted ﬁsh, cephalopods, and other marine animals. 
   
  ■ When  Early to mid Jurassic 
   
  ■ Fossil location  Argentina, UK, France, Germany 
   
  ■ Habitat  Shallow oceans 
   
  ■ Size  13 ft (4 m) long  
  Like its close relative Ichthyosaurus, 
  Stenopterygius was a dolphinlike reptile 
  adapted to catching ﬁsh in its tooth-ﬁlled 
  snout. Its streamlined shape and muscular ﬁns 
  suggest it could achieve a top speed of perhaps 
  60 mph (100 kph), enabling it to blast into 
  shoals of ﬁsh like a torpedo and snatch prey  
  in the resulting confusion.
  Stenopterygius
  stenOPterr-idge-ee-us
  Dorsal ﬁn
  Backbone bends downward 
  to support the tail.
  In most large fossils only bones are 
  visible, but in this remarkable 
  Stenopterygius fossil, the ﬁns, tail, 
  and other soft tissues can be seen.
  Short hind limb
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  109
  EARLY VERTEBRATES
  Nostril
  Jaws
  Snout with teeth 
  for grasping prey.
  Huge eye socket
  Birth of young 
  Although ichthyosaurs lived millions of years ago, 
  we know that these marine animals gave birth to 
  live young rather than laying eggs. How do we 
  know? It’s because fossils have been discovered 
  that show females giving birth (always tail ﬁrst). 
  However, it’s highly unlikely that the parent cared 
  for its young after birth.
  251 million years ago
  200
  145
  65
  Triassic
  Jurassic
  Cretaceous
  . ICHTHYOSAUR YOUNG, 
  such as this Stenopterygius, 
  were probably self-suﬃcient  
  soon after birth.
  Studies of  
  Stenopterygius’s 
  beautifully preserved fossils suggest  
  it was a fast swimmer—at least  
  as swift as the fastest ﬁsh  
  alive today.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  A young fossil hunter
  In 1830, English geologist Henry De la Beche painted  
  a curious watercolor with the intention of selling copies 
  to raise money for a friend. The friend was Mary Anning, 
  and the painting was the ﬁrst time anyone had tried to 
  draw a realistic picture of prehistoric life. Most amazing 
  of all, Mary had discovered every animal in it.
  EARLY VERTEBRATES
  The painting showed an 
  ichthyosaur capturing  
  a plesiosaur.
  United 
  Kingdom
  Dorset
  A look back in time
  De la Beche called his painting Duria 
  Antiquior, or “A more ancient Dorset.” 
  It featured animals that Mary had found  
  as fossils on the coast of Dorset in England. 
  Prints of this painting were passed around 
  scientiﬁc circles in the 1800s, and inﬂuenced 
  thinking on prehistoric life.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  111
  WHO WAS MARY ANNING?
  Mary Anning (1799–1847) was just 
  11 years old when her brother found 
  the head of a large fossil on a beach. 
  She was to become one of the most 
  famous of all fossil hunters. Anning 
  was never taken as seriously as she 
  should have been because she was a 
  woman and from a poor background, 
  whereas most scientists of the time 
  were men from wealthy families.
  More amazing finds
  The cliﬀs near where Anning lived are rich in fossils from the Jurassic Period.  
  She found the ﬁrst plesiosaur there in 1823 and the ﬁrst pterosaur in 1828.  
  She carefully recorded each ﬁnd, before selling the fossils.
  WHAT WAS IT?
  Anning spent months uncovering the body of her ﬁrst fossil.  
  It was later named Ichthyosaurus, which means “ﬁsh lizard.” 
  This marine reptile swam in the time of the dinosaurs.
  EARLY VERTEBRATES
  A precious notebook
  Anning’s life was not easy 
  and was largely spent in 
  poverty. She and one 
  brother were the only 
  survivors of 10 children, 
  and she lacked an 
  education. However, she 
  managed to teach herself 
  about the fossils she found 
  and kept careful notes and 
  sketches detailing each 
  ﬁnd. Over the years, her 
  fossil-hunting successes  
  would bring her  
  huge recognition.
  , HIDDEN TREASURES 
  The cliﬀs at Lyme Regis bay, where 
  Anning hunted for fossils, are still 
  an exciting place for fossil hunters.
  u WHAT BIG EYES! Huge eye 
  sockets suggest that ichthyosaurs 
  depended on their vision to hunt. 
  They may even have hunted at 
  night or in deep, dark waters.
  Plesiosaur sketch
  by Mary Anning
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  112
  EARLY VERTEBRATES
  Mosasaurs 
  Just before the end of the Cretaceous Period,  
  the seas were home to gigantic lizards as 
  terrifying and as huge as any mythological  
  sea serpent. Called mosasaurs, these monsters 
  were close relatives of today’s lizards and 
  snakes. They evolved from small, land-living 
  lizards that took to the water in search of food. 
  As the lizards adapted to life in the sea, their 
  legs turned into flippers and their bodies, 
  supported by water, became enormous.
   
  ■ When  70–65 million years ago (Late Cretaceous) 
   
  ■ Fossil location  USA, Belgium, Japan, Netherlands, New Zealand, 
  Morocco, Turkey 
   
  ■ Habitat  Oceans 
   
  ■ Length  About 50 ft (15 m) 
   
  ■ Diet  Fish, squid, and shellﬁsh
  Mosasaurus was one of the largest mosasaurs. It looked a bit like 
  a crocodile with flippers, and swam by moving its long body in 
  slow waves. As a result, it couldn’t swim fast over long distances, 
  but might have been capable of sudden bursts of speed. Scientists 
  think Mosasaurus lived in the well-lit surface waters of oceans, 
  hunting slower-moving prey. Bite marks left by its huge, 
  conical teeth have been found on turtle shells and 
  ammonites. Mosasaurus survived to the end of the 
  Cretaceous, when it vanished with the dinosaurs.
  Mosasaurus
  MOSE-ah-saw-rus
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  113
  EARLY VERTEBRATES
   
  ■ When  85–80 million years ago (Late Cretaceous) 
   
  ■ Fossil location  Worldwide 
   
  ■ Habitat  Oceans 
   
  ■ Length  14 ft (4.2 m) 
  Platecarpus was not the largest mosasaur 
  but it was certainly was one of the most 
  abundant. Its fossils have 
  been found worldwide,  
  most commonly in the 
  Niobrara chalk beds of 
  Platecarpus
  PLAH-teh-CAR-pus
  North America. Like other mosasaurs, 
  Platecarpus used its long, muscular tail 
  to drive itself through water in a zigzag, 
  snakelike manner. It had fewer and smaller 
  teeth than other mosasaurs, suggesting a  
  diet of softer prey such as fish and squid.  
  The belly of one specimen was found to 
  contain fish scales and fish bones—the 
  remains of one of its last meals.
  In the Cretaceous, an ocean ran 
   down the middle of North America, 
  cutting the continent in two. Its muddy 
  bed has now turned to rock, forming 
  the Niobrara chalk of North America. 
  Niobrara chalk contains a wealth  
  of amazing fossils, including 
  mosasaurs and plesiosaurs.
  FAMILY FACT FILE
  Key features
   
  ■ Lizardlike bodies with flippers
   
  ■ Powerful jaws lined with sharp teeth
   
  ■ Breathed air at the water surface
  When
  Mosasaurs lived in the Cretaceous Period, 
  between 85 and 65 million years ago. 
  They were killed along with dinosaurs 
  and most other large reptiles in the mass 
  extinction at the end of the Period.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  114
  DINOSAURS 
  and BIRDS
  DINOSAURS AND BIRDS
  u QUARRY FIND Traces of dinosaurs 
  have been found the world over. Quarries 
  sometimes turn up fabulous ﬁnds, such as 
  the dinosaur footprints running across a 
  rock face at this quarry in Sucre, Bolivia.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  115
  Dinosaurs were the 
  dominant land animals on 
  Earth for an unimaginably 
  vast span of time: 160 
  million years. They were 
  not entirely wiped out, 
  and their descendants the 
  birds survive to this day.
  DINOSAURS AND BIRDS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  116
  KILLER JAWS
  Vast jaw muscles gave Tyrannosaurus possibly the most 
  powerful bite of any animal in history. Its teeth were 
  rock-solid spikes of enamel, able to puncture bone, 
  hide, and muscle to inﬂict horrible injuries on animals 
  that weren’t crushed to death instantly.
  DINOSAURS AND BIRDS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  DINOSAURS AND BIRDS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  118
  Key features
   
  ■ Lived on land
   
  ■ Built nests and laid eggs
   
  ■  Most had scaly skin (some had 
  feathers)
   
  ■ Long tails, held off the ground
   
  ■  Walked on upright, pillarlike 
  legs.
  What are dinosaurs?
  Dinosaurs survived for an astounding 
  160 million years (humans, in contrast, 
  have existed for less than one million 
  years). Ranging in size from animals no 
  bigger than pigeons to lumbering 
  giants the size of a truck, 
  they were reptiles, but 
  very diﬀerent from 
  modern-day 
  reptiles.
  FAMILY TREE
  Dinosaurs can be split into two groups: the 
  saurischians (or lizard-hipped dinosaurs) and the 
  ornithischians (or bird-hipped dinosaurs). These  
  can be split further, as shown below.
  DINOSAURS AND BIRDS
  ORNITHISCHIANS
  Theropods
  SAURISCHIANS
  Ornithopods
  Sauropodomorphs
  Thyreophorans
  DINOSAURS
  Marginocephalians
  One way in which dinosaurs diﬀered from today’s reptiles and 
  lizards is that they could stand with their legs straight, in the 
  same way as mammals. Some dinosaurs walked on two legs, 
  some on four. Some may have done both.
  u DINOSAURS 
  walked on upright, 
  pillarlike legs.
  u CROCODILES
  walked with knees 
  and elbows bent.
  u LIZARDS hold 
  their legs at right- 
  angles to the body.
  FACT FILE
   
  ■  Holes (“windows”) in the 
  skulls of larger dinosaurs, 
  making them lighter. (Only 
  the armored dinosaurs had 
  solid skulls.)
   
  ■ Walked on their toes
   
  ■ Claws on fingers and toes
  , WE’RE STILL HERE! Most 
  scientists believe that birds are  
  the living descendants of small, 
  meat-eating dinosaurs.
  Also called armored dinosaurs, members of this group of 
  plant-eaters were large, walked on four feet, and had armor plates 
  and spikes that protected them from attack. Some of these 
  dinosaurs even had armored eyelids!
  THYREOPHORANS (THIGH-ree-OFF-oh-rans)
  , KENTROSAURUS
  had a double row of  
  bony plates running  
  along the center  
  of its back.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  119
  This group of plant-eaters had heads that sported bony frills. 
  (Marginocephalian means “fringed head.”) Some walked on 
  two legs, some on four. They were common dinosaurs in the 
  Cretaceous and included the well-known Triceratops.
  MARGINOCEPHALIANS (MAR-jee-no-sa-FAY-lee-ans)
  These plant-eaters all roamed on two legs, so were able to use 
  their forelimbs to grasp their food. They were immensely 
  successful and very common. Fossils of these types of  
  dinosaur have been found all over the world.
  ORNITHOPODS (OR-nith-oh-pods)
  This group contained the heaviest and longest animals ever to 
  walk on Earth. They were herbivores (plant-eaters) and would 
  have had to graze constantly to obtain the energy they needed.
  SAUROPODOMORPHS (SORE-oh-POD-oh-morfs)
  u BRACHIOSAURUS 
  Sauropods had tiny heads 
  compared to their bodies.
  u EINIOSAURUS
  had a forward- 
  curving horn.
  u IGUANODON, an 
  ornithopod, was the second 
  dinosaur to be named.
  All meat-eating dinosaurs were saurischians, and they formed a 
  group called the theropods. This is the group from which birds 
  are descended. They ranged in size from the chicken-sized 
  Compsognathus to monsters such as the mighty Spinosaurus.
  THEROPODS (THERRO-pods)
  , SPINOSAURUS 
  had a massive skin 
  “sail” that ran the 
  length of its back.
  DINOSAURS AND BIRDS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  120
  DINOSAURS AND BIRDS
  Small ornithischians
  The dinosaur family tree is split into two halves: saurischians 
  and ornithischians. The ornithischians were plant-eaters 
  with beaked jaws for plucking leaves and large bellies for 
  digesting them. Though some ornithischians were huge, 
  four-footed giants, many were small, two-footed herbivores 
  that scurried about nervously in forests and scrublands, 
  searching for food and trying to avoid predators.
   
  ■ When  200–190 million years ago (Early Jurassic)
   
  ■ Fossil location  S. Africa
   
  ■ Habitat  Scrubland
   
  ■ Length  3 ft (1 m)
   
  ■ Diet  Plants, tubers, possibly insects
  Unlike most dinosaurs, which had one type of 
  tooth, Heterodontosaurus (“diﬀerent-toothed 
  lizard”) had three types. Its sharp front teeth 
  snipped oﬀ tough vegetation, which was then 
  mashed to a pulp with its cheek teeth. It also 
  Heterodontosaurus
  HET-er-oh-DON-toe-SORE-us
  FAMILY FACT FILE
  Key features
   
  ■ Plant-eaters
   
  ■ Beaked jaws
   
  ■ Back-pointing pubis bone
   
  ■ Large belly for digesting vegetation
  When
  Ornithischians lived from the beginning 
  of the Jurassic Period, 200 million years 
  ago, to the end of the Cretaceous Period, 
  65 million years ago.
  had large, fanglike teeth to defend itself 
  against enemies. The jaws were tipped  
  with a horny beak that was probably  
  used for plucking leaves.
  , FOSSIL 
  Heterodontosaurus’s complete 
  skeleton was found in 1976 
  with every bone in place.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  121
  DINOSAURS AND BIRDS
   
  ■ When  200–190 million years ago (Early Jurassic)
   
  ■ Fossil location  S. Africa
   
  ■ Habitat  Desert plains
   
  ■ Length  3 ft (1 m)
   
  ■ Diet  Leaves, perhaps dead animals and insects
  This dinosaur was named after Lesotho, the south African country where 
  its fossils were ﬁrst found in 1978. Scientists think Lesothosaurus was 
  similar to a modern gazelle, grazing on low-lying plants and running 
  away quickly at the ﬁrst sight of predators. Its upper and lower teeth 
  were small and shaped like arrowheads.
   
  ■ When  125–120 million years ago 
  (Early Cretaceous)
   
  ■ Fossil location  England, Spain
   
  ■ Habitat  Forests
   
  ■ Length  7 ft (2 m)
   
  ■ Diet  Plants
  Hypsilophodon was much like a modern deer, grazing on tender 
  plants with its small, leaf-shaped teeth. Fossil footprints grouped 
  together hint that these creatures roamed in herds like deer, though 
  this is far from certain. Its stiﬀ tail and long legs and feet show it  
  was a fast-running ground animal, able to ﬂee swiftly from predators 
  on its hind legs while using its tail for balance.
   
  ■ When  105 million years ago (Early Cretaceous)
   
  ■ Fossil location  Australia
   
  ■ Habitat  Forests
   
  ■ Length  7 ft (2 m)
   
  ■ Diet  Plants
  Leaellynasaura lived near the South Pole. 
  Although it was less cold here during  
  the Cretaceous Period than it is today, 
  Leaellynasaura would have had to live without sunlight 
  for several months of the year during polar winters. It 
  had large eyes, which helped it see better in the dark 
  and avoid predators. It was probably warm-blooded.
  Lesothosaurus
  li-SUE-too-SORE-us
  Hypsilophodon
  HIP-sih-LOAF-oh-don
  Leaellynasaura
  lee-ELL-in-ah-SORE-ah
  Othnielosaurus
  oth-nee-ELL-oh-SORE-us
   
  ■ When  155–145 million years ago (Late Jurassic)
   
  ■ Fossil location  USA
   
  ■ Habitat  Plains
   
  ■ Length  7 ft (2 m)
   
  ■ Diet  Plants
  Othnielosaurus moved swiftly on its 
  strong back limbs, which were built for 
  running. Its front limbs were short and 
  weak, and its hands and ﬁngers were 
  small. Fossils show that its teeth 
  were edged with many small ridges, making 
  them well-suited for shredding leaves. Its 
  vertebrae show that it had a short neck.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  122
  Pachycephalosaurus
  This herbivore had a mysterious dome of solid bone at 
  the top of its skull, but what for? One old theory is that 
  males had head-butting contests like rams—but their 
  curved necks might not have been able to take the force. 
  Another theory is that they swung their heavy heads 
  sideways at each other like giraffes. Or perhaps their 
  fancy heads merely served to impress mates and rivals.
  DINOSAURS AND BIRDS
  Dome
  Small teeth
  DID YOU KNOW...?
  Pachycephalosaurus is known only from 
  one complete skull (a replica of which is 
  shown below) and a few skull fragments. 
  The dome of thick bone on its skull was 
  fringed by bony knobs and spikes, which 
  may have been used for display. Its teeth 
  were tiny and its eyes large.
  Last of the 
  dinosaurs
  Pachycephalosaurus lived at the 
  end of the Cretaceous Period 
  and was one of the species 
  wiped out in the dinosaurs’ 
  mass extinction.
  Large eye sockets
  251 million years ago
  200
  145
  65
  Triassic
  Jurassic
  Cretaceous
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  123
   
  ■ When  65 million years ago (Late Cretaceous) 
   
  ■ Fossil location  N. America
   
  ■ Habitat  Forests of N. America
   
  ■ Length  16 ft (5 m)
   
  ■ Diet  Plants, soft fruit, seeds
  By comparing Pachycephalosaurus’s few fossils 
  with those of its relatives, scientists figure that this 
  dinosaur was about as long as a station wagon.  
  It probably had a bulky body but the long, slender 
  hind legs of a fast runner. Its small teeth suggest a 
  diet of easily digested plants or, perhaps, a mixture 
  of plants and animal foods such as eggs.
  Pachycephalosaurus
  PACK-ee-sef-ah-low-SORE-us
  DINOSAURS AND BIRDS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  Ceratopsians
  The plant-eating ceratopsians varied from sheep-sized 
  animals to sturdy giants that were bigger than elephants. 
  They grazed in the forests and plains of North America 
  and Asia, perhaps in herds. They had huge, parrotlike 
  beaks that they used to grasp and rip up plants. With 
  their towering horns and huge neck frills, they must  
  have been a spectacular sight. 
  FAMILY FACT FILE
  Key features
   
  ■ Massive hooked beaks for grasping plants
   
  ■ Hundreds of chisel-edged teeth for 
  slicing through leaves like scissors
   
  ■ Large horns and neck frills, mainly  
  for display
   
  ■ Short legs
   
  ■ Hooflike bones on fingers and toes
  When
  These dinosaurs thrived in the Cretaceous 
  Period, around 80 million years ago.  
  The last of the ceratopsians died out in 
  the mass extinction at the end of the 
  Cretaceous Period, 65 million years ago.
  DINOSAURS AND BIRDS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  125
  Sturdy leg
   
  ■ When  74–65 million years ago (Late Cretaceous)
   
  ■ Fossil location  N. America 
   
  ■ Habitat  Woodland 
   
  ■ Length  16 ft (5 m) 
   
  ■ Diet  Palms and cycads 
  Chasmosaurus’s neck frill has huge holes 
  that would have been covered by skin. 
  The frill could have been tilted upright  
  to attract attention or startle enemies  
  and may have been brightly colored.
  Chasmosaurus
  KAS-mo-SAWR-uss
   
  ■ When  74–65 million years ago (Late Cretaceous) 
   
  ■ Fossil location  N. America 
   
  ■ Habitat  Open woodland 
   
  ■ Length  17 ft (5.2 m) 
   
  ■ Diet  Ferns and cycads
  Styracosaurus’s magnificent frill sported 
  six spikes up to 2 ft (60 cm) long that may 
  have served as decoration to attract mates. 
  Styracosaurus had a large, deep snout with 
  huge nostrils, and a short, blunt horn.  
  Its sharp teeth could cut through thick  
  vegetation and were constantly replaced.
  Styracosaurus
  sty-RACK-oh-SORE-uss
   
  ■ When  74–65 million years ago (Late Cretaceous) 
   
  ■ Fossil location  USA 
   
  ■ Habitat  Wooded plains 
   
  ■ Length  16–26 ft (5–8 m) 
   
  ■ Diet  Plants
  A huge head was the most remarkable feature 
  of this dinosaur. One fossil skull, built from 
  broken fragments, is more than 10 ft (3 m) 
  long, making it the longest skull of any  
  land animal in history. Pentaceratops means 
  “five-horned face”—the dinosaur had one 
  horn on the snout, two curved horns on  
  the brow, and a small horn on each cheek. 
  Pentaceratops
  PEN-ta-SERRA-tops
   
  ■ When  74–65 million years ago (Late Cretaceous)
   
  ■ Fossil location  Mongolia
   
  ■ Habitat  Desert 
   
  ■ Length  6 ft (1.8 m) 
   
  ■ Diet  Desert plants 
  Many well-preserved fossils of this small 
  ceratopsian have been found in Mongolia’s 
  Gobi Desert. Protoceratops had a wide neck 
  frill at the back of its skull that expanded with 
  age and was larger in males. It also had broad, 
  spadelike claws, perhaps for digging burrows.
  Protoceratops
  PRO-toe-SERRA-tops
   
  ■ When  74–65 million years ago 
  (Late Cretaceous)
   
  ■ Fossil location  USA 
   
  ■ Habitat  Woodland
   
  ■ Length  20 ft (6 m) 
   
  ■ Diet  Plants
  In 1985, scientists found fossils  
  of 15 Einiosaurus individuals in the 
  same site in the USA—perhaps they 
  were members of a herd that died 
  together in a flood or landslide. 
  Einiosaurus had an impressive 
  frill with a wavy margin and two 
  long horns that pointed upward. 
  The horns were probably used  
  for both display and fighting.
  Einiosaurus
  ie-nee-o-SAWR-uss
  Tiny horn 
  between eyes
  DINOSAURS AND BIRDS
  Hole in frill
  Parrotlike beak
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  126
  Triceratops
   
  ■ When  70–65 million years ago (Late Cretaceous)
   
  ■ Fossil location  N. America 
   
  ■ Habitat  Woodland 
   
  ■ Length  30 ft (9 m) 
   
  ■ Diet  Forest plants 
  Triceratops’s neck was probably quite flexible, 
  helping it to feed not only on tree leaves but also 
  on low-growing plants. Its powerful parrotlike 
  beak helped it pluck tough forest vegetation, such 
  as palms, ferns, and cycads. Its teeth were like 
  scissors—shredding and snipping the plants. 
  Triceratops
  try-SERRA-tops
  DINOSAURS AND BIRDS
  Bite marks left by the ferocious 
  Tyrannosaurus on some Triceratops skulls 
  suggest there were fierce clashes between 
  the two species millions of years ago.  
  One Triceratops even seems 
  to have had a brow  
  horn snapped off. 
  BATTLE  
  SCARS
  Brow horn over 
  3 ft (1 m) long
  As heavy as a 10-ton truck, Triceratops 
  was built like a huge rhinoceros. It gets  
  its name (“three-horned face”) from  
  the short nose horn and two longer 
  brow horns. Triceratops used its 
  horns and frills like deers use  
  their antlers—to attract mates.
  Single row of teeth on 
  each side of lower jaw
  251 million years ago
  200
  145
  65
  Triassic
  Jurassic
  Cretaceous
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  127
  . FRILL
  Around the back of 
  Triceratops’s skull was a 
  huge frill made of bone. The 
  horns and frill were once thought  
  to be used for defence, but many 
  experts now believe they were  
  used to attract females during  
  the mating season.
  DINOSAURS AND BIRDS
  Torosaurus 
  skull
  Window 
  in frill
  . TOROSAURUS
  The dinosaur 
  Torosaurus was very 
  much like Triceratops but 
  had a larger frill with windows in 
  it. Some scientists are unsure whether 
  Torosaurus was a separate species and wonder 
  if it may simply have been a mature Triceratops 
  in which the shield had developed windows. 
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  128
  DINOSAURS AND BIRDS
  Iguanodontians
  The iguanodontians were among the most common  
  and widespread dinosaurs of the Late Jurassic and  
  the Cretaceous. They varied from small, nondescript 
  dinosaurs to giants with horselike faces and huge sails on 
  their backs, but all had beaked mouths for eating plants. 
  The iguanodontian group also includes the 
  large duck-billed dinosaur family 
  (next page).
  Key features
   
  ■ Toothless beaks for clipping plants
   
  ■ Hooflike claws
   
  ■ Mobile jaws able to chew plants
   
  ■ Stiff tails
  When
  Iguanodontians appeared 156 million 
  years ago, in the Late Jurassic Period. 
  They died out at the end of the 
  Cretaceous Period, 65 million years ago.
   
  ■ When  135–125 million years ago (Early Cretaceous)
   
  ■ Fossil location  Belgium, Germany, France, 
  Spain, England
   
  ■ Habitat  Woodlands
   
  ■ Length  30 ft (9 m)
   
  ■ Diet  Plants
  Discovered in the 1820s, Iguanodon was the 
  second prehistoric animal to be identified  
  as a dinosaur. Its name means “iguana teeth” 
  as its teeth looked like those of an iguana 
  but were 20 times bigger. Iguanodon was as 
  Iguanodon
  ig-GWAH-no-don
  big as an elephant and walked mainly on all  
  fours, feeding on low-growing plants. Its hind legs 
  were larger and more powerful than its front legs, 
  allowing it to stand and perhaps run on two feet.
  . HANDY 
  The three middle fingers  
  of Iguanodon’s hands 
  were joined to form a 
  hoof. It could fold its 
  little finger across its palm 
  to grasp objects, and its  
  thumb had a vicious spike,  
  perhaps for self-defense.
  Thumb 
  spike
  Little finger
  FAMILY FACT FILE
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  129
  DINOSAURS AND BIRDS
  Short arms may 
  have meant it 
  couldn’t go down 
  on all fours.
   
  ■ When  155–145 million 
  years ago (Late Jurassic)
   
  ■ Fossil location  USA
   
  ■ Habitat  Woodlands
   
  ■ Length  10 ft (3 m)
   
  ■ Diet  Leaves and shoots
  This small and lightly built herbivore  
  had long and powerful legs—a sign that it 
  was a fast runner. It had a stiff tail to help 
  balance its body while running and may 
  have flicked the tail sideways to make sharp  
  turns to dodge obstacles or outwit pursuers.
   
  ■ When  115–108 million years ago (Early Cretaceous)
   
  ■ Fossil location  USA
   
  ■ Habitat  Woodlands
   
  ■ Length  23 ft (7 m)
   
  ■ Diet  Plants
  Some dinosaurs are famous for 
  having served as lunch for others. 
  Tenontosaurus was one such unfortunate 
  creature. Remains of this herbivore  
  are often found with teeth of the 
  small but ferocious carnivore 
  Deinonychus, which may have 
   
  ■ When  100–98 million years ago 
  (Early Cretaceous)
   
  ■ Fossil location  Australia
   
  ■ Habitat  Woodlands
   
  ■ Length  23 ft (7 m)
   
  ■ Diet  Plants
  The bone forming the top of Muttaburrasaurus’s snout 
  bulged upward, giving this dinosaur an arched nose.  
  It may have used its large nasal chambers to create honking 
  sounds or to warm cold air as it breathed in. The size  
  and shape of its snout differed between individuals and 
  probably varied with sex and age.
  Camptosaurus
  CAMP-toe-SORE-us
  Dryosaurus
  DRY-oh-SORE-us
  Tenontosaurus
  ten-NON-toe-SORE-us
  Muttaburrasaurus
  MOO-tah-BUH-ruh-SORE-us
  brought down the bigger dinosaur by hunting 
  in packs. Bones of both have also been found 
  together, suggesting that Deinonychus didn’t 
  always survive the battles. 
   
  ■ When  155–145 million years ago (Late Jurassic)
   
  ■ Fossil location  USA
   
  ■ Habitat  Open woodlands
   
  ■ Length  16 ft (5 m)
   
  ■ Diet  Low-growing herbs and shrubs
  Camptosaurus was one of the most common 
  iguanodontians and looked like a small 
  version of Iguanodon, with a similar long, 
  horselike face tipped by a beak. Its hands,  
  like those of Iguanodon, had hooflike 
  middle fingers and a thumb spike. 
  Long, horselike face
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  130
  Hadrosaurids
  Also known as “duck-billed” dinosaurs, the hadrosaurids 
  were large plant-eaters with distinctive, ducklike bills 
  that they used to clip leaves from plants. Hadrosaurids 
  may have lived in large herds, and some types seem  
  to have formed nesting colonies in which parents  
  nursed their young after hatching. 
   
  ■ When  80–74 million years ago 
  (Late Cretaceous)
   
  ■ Fossil location  USA 
   
  ■ Habitat  Coastal plains 
   
  ■ Length  30 ft (9 m)  
   
  ■ Diet  Leaves
  The name Maiasaura means “good mother 
  lizard.” In Montana, scientists found 
  numerous bowl-shaped Maiasaura nests 
  close together. The site may have been a 
  nesting colony where parents raised their 
  young, like nesting colonies  
  of modern seabirds.
  Maiasaura
  MY-a-SORE-a
  DINOSAURS AND BIRDS
  FAMILY FACT FILE
  Key features
   
  ■ Ducklike bills
   
  ■ Rear of mouth was packed with 
  thousands of teeth for grinding leaves
   
  ■ Forelimbs were half as long as 
  hindlimbs
   
  ■ Many hadrosaurids had strangely 
  shaped crests on their heads
  When
  Hadrosaurids lived in the Cretaceous 
  Period, between 100 and 65 million  
  years ago.
  u FAMILY LIFE Fossilized eggshell pieces 
  and young Maiasaura were discovered in nests 
  in Montana. The presence of young animals 
  suggests that hatchlings stayed in the nest 
  while being looked after, just as many baby 
  birds do, rather than leaving immediately as 
  newly hatched turtles and crocodiles do.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  131
   
  ■ When  80–74 million years ago (Late Cretaceous)
   
  ■ Fossil location  N. America 
   
  ■ Habitat  Woodlands 
   
  ■ Length  30 ft (9 m) 
   
  ■ Diet  Leaves and twigs
  This was one of the first dinosaurs  
  discovered in North America. Hadrosaurus 
  used a toothless beak to tear twigs and leaves 
  from plants before grinding them to a pulp 
  with hundreds of tiny teeth located in  
  the back of its mouth.
  Hadrosaurus
  HAD-roh-SORE-uss
   
  ■ When  76–74 million years ago (Late Cretaceous)
   
  ■ Fossil location  N. America 
   
  ■ Habitat  Woodlands 
   
  ■ Length  30 ft (9 m) 
   
  ■ Diet  Leaves, seeds, and pine needles
  This creature’s head had  
  a long, tubelike crest 
  containing hollow tubes. 
  Perhaps Parasaurolophus 
  tooted air out of the crest 
  to make trumpetlike sounds  
  to communicate with herd 
  members. Its heavy, muscular 
  build and wide shoulders 
  may have helped it push 
  through dense under-
  growth in woodlands.
  Parasaurolophus
  PA-ra-SORE-oh-LOAF-uss
   
  ■ When  65–85 million years ago (Late Cretaceous) 
   
  ■ Fossil location  N. America 
   
  ■ Habitat  Woodlands 
   
  ■ Length  30 ft (9 m)  
   
  ■ Diet  Vegetation
  Gryposaurus’s large, hooked nose looked like 
  a rounded beak. Rivals may have settled 
  contests by butting noses and shoving each 
  other. Gryposaurus also had very long arms for 
  a hadrosaurid—perhaps they helped it reach 
  higher leaves. Skin impressions suggest the 
  animal had pyramid-shaped scales on its back. 
  Gryposaurus
  GRIP-o-SAWR-us
  u STIFF TAIL 
  All hadrosaurids had stiff,  
  horizontal tails, the tail bones 
  interlocking to prevent sagging.
   
  ■ When  76–74 million years ago (Late Cretaceous) 
   
  ■ Fossil location  Canada 
   
  ■ Habitat  Woodlands 
   
  ■ Length  30 ft (9 m) 
   
  ■ Diet  Low-growing leaves, fruits, and seeds  
  Lambeosaurus’s hollow crest was shaped 
  like a hatchet. Perhaps the 
  distinctive shape enabled 
  this dinosaur to recognize 
  others of its species quickly. 
  The crest’s shape varied 
  between the sexes, 
  suggesting that 
  males used theirs 
  to impress females.
  Lambeosaurus
  LAMB-ee-oh-SORE-uss
   
  ■ When  75–65 million years ago (Late Cretaceous)
   
  ■ Fossil location  N. America 
   
  ■ Habitat  Woodlands
   
  ■ Length  30 ft (9 m) 
   
  ■ Diet  Ferns, magnolias, and conifers
  Brachylophosaurus had a deep snout and a 
  rectangular skull with a flat, paddle-shaped 
  crest on its head. Males had wider crests and 
  were more heavily built than females. In 2000, 
  a near-perfect fossil skeleton was found in 
  Montana. Large areas of its body were  
  covered with an impression of its scaly skin. 
  Brachylophosaurus
  BRACK-ee-LOAF-oh-SORE-uss
  Long, slender 
  thigh bone
  The crest’s shape  
  changed as the 
  hadrosaurid grew  
  into an adult. 
  Deep snout
  Wide tip 
  of jaw
  DINOSAURS AND BIRDS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  132
  Dinosaur droppings
  Perhaps the most surprising of all dinosaur fossils are 
  coprolites—fossilized poop. Coprolites have been found 
  all over the world, since they were ﬁrst recognized for 
  what they were in the 1830s. They can tell us a lot 
  about dinosaurs, most importantly, what they ate.
  DINOSAURS AND BIRDS
  Let’s use it!
  In the nineteenth century, coprolites were 
  actually mined in parts of England and 
  turned into fertilizer. They were rich in 
  a substance called phosphate that was 
  needed to help crops grow to feed  
  a quickly expanding population.
  AN UNUSUAL COLLECTION
  Karen Chin is a world expert on 
  fossilized dinosaur dung and has 
  a huge collection of coprolites. 
  She cuts slices to look at 
  under a microscope and 
  discover what is 
  inside—whether it be 
  small bones or leaves  
  or seeds.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  133
  DINOSAURS AND BIRDS
  One of the biggest
  The huge coprolite below was found  
  to contain chewed bits of bone from  
  a cow-sized meat-eating dinosaur. It’s 
  thought to have been a Tyrannosaurus’s 
  dropping and measures 15 inches (38 cm) 
  in length, although fragments found 
  nearby suggest it was originally larger. 
  Few dinosaur coprolites are preserved 
  exactly as they were formed, and it’s tricky 
  to link them to a particular dinosaur.
  u FRAGMENTS of bone found in this 
  Tyrannosaurus coprolite show that the 
  predator swallowed bones as well as ﬂesh.
  It’s a dropping!
  The fossil hunter Mary Anning (see pages 
  110–111) found stones in the belly region 
  of the fossils she uncovered and described 
  them as containing fossilized ﬁsh bones. 
  Based on her ﬁnds, scientist William 
  Buckland gave them the Greek name 
  coprolites, meaning “dung stones.” 
  FACT FILE
  Karen Chin found small, fossilized 
  burrows in the coprolites of plant-eating 
  dinosaurs. With this evidence, she 
  discovered that dung beetles were 
  clearing dung in the age of the  
  dinosaurs, just as they do today.
  u DUNG BEETLE with dung ball.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  134
  Corythosaurus
  Several complete skeletons of Corythosaurus were found in
  North America, making it one of the best-known members  
  of the hadrosaurid family. This crested, duck-billed dinosaur 
  wandered through the swamps and woodlands of the region 
  75 million years ago, perhaps in herds. Its crest may have  
  been used as a trumpet to keep 
  in touch with the herd. 
  WOODLAND HABITAT
  Like most hadrosaurids, Corythosaurus lived in 
  woodlands covering warm plains near the Rocky 
  Mountains in North America. Its snout was smaller 
  and more delicate than those of other hadrosaurids, 
  suggesting a diet of tender leaves and juicy fruits.
  DINOSAURS AND BIRDS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  135
   
  ■ When  76–74 million years ago (Late Cretaceous)
   
  ■ Fossil location  Canada, N. America
   
  ■ Habitat  Forests and swampy areas 
   
  ■ Length  30 ft (9 m)
   
  ■ Diet  Leaves, seeds, and pine needles
  Corythosaurus was one of the larger 
  hadrosaurids. Tall, bony spines on its back  
  were covered with a frill of skin that formed  
  a ridge running along its back. This frill  
  was very prominent at the back of the head 
  crest, where it was attached. 
  Corythosaurus
  ko-RITH-oh-SORE-us
  u FOSSILIZED SKIN
  Of the skeletons discovered, some had 
  well-preserved impressions of skin. A few  
  of these showed that Corythosaurus’s belly 
  had strange, wartlike lumps.
  135
  Corythosaurus means “helmet lizard." 
  Scientists named it so because of the 
  crest on its head, which reminded 
  them of helmets worn by the 
  soldiers of ancient Greece. 
  Headdress 
  u SKULL
  Corythosaurus’s crest may have worked like 
  a trombone, amplifying sound to make loud, 
  booming calls that carried a long way. Perhaps 
  these served as warning signals to alert other  
  herd members of predators lurking nearby.
  Hollow crest
  Tubes in 
  nostrils were 
  connected  
  to crest. 
  DINOSAURS AND BIRDS
  251 million years ago
  200
  145
  65
  Triassic
  Jurassic
  Cretaceous
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  136
  DINOSAURS AND BIRDS
  Edmontosaurus
  Twice as big as a fire truck, Edmontosaurus was one of the 
  largest duck-billed dinosaurs (hadrosaurids) and lived 
  alongside other giant dinosaurs such as Triceratops and 
  Tyrannosaurus, about 66 million years ago. Like other 
  hadrosaurids, Edmontosaurus had a ducklike bill for 
  cropping leaves, but its head had no crest.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  137
  DINOSAURS AND BIRDS
   
  ■ When  75–65 million years ago (Late Cretaceous)
   
  ■ Fossil location  USA, Canada 
   
  ■ Habitat  Swamps of N. America 
   
  ■ Length  43 ft (13 m) long  
   
  ■ Diet  Plants 
  Edmontosaurus is named after Edmonton 
  town in Alberta, Canada, where the ﬁrst  
  fossils were found in 1917. One of the largest 
  hadrosaurids, it weighed up to 4½ tons  
  (4 metric tons). Hollow areas around its 
  nostrils may have contained inﬂatable sacs 
  that Edmontosaurus could expand like balloons 
  and perhaps use to make sounds.
  Edmontosaurus
  ed-MONT-oh-SORE-us
  u SKIN IMPRESSION Fossilized skin 
  impressions reveal that Edmontosaurus 
  had scaly skin with large bumps. 
  . STANDING TALL 
  Edmontosaurus walked on four 
  feet and could bend low to reach 
  plants on the ground. It could also 
  rear up on its hind legs to reach 
  higher branches, but it couldn’t 
  run on its hind legs.
  u MOUTH Edmontosaurus 
  had a broad beak for cropping 
  leaves. The back of its mouth 
  was packed with hundreds  
  of tiny teeth for chewing.  
  The teeth were continually 
  replaced, with new ones  
  taking perhaps a year to form.
  Dinosaur “mummies” 
  Some very well-preserved Edmontosaurus 
  fossils have been found, including fossils  
  of mummiﬁed bodies that show skin and 
  other soft tissues. These animals seem to 
  have died in a hot, dry location where the 
  body dried out quickly after death, before 
  soft tissues could decompose. At some 
  later date, the mummies were buried in 
  soft mud or sand, preserving an imprint 
  of the skin.
  Preserved 
  skin
  251 million years ago
  200
  145
  65
  Triassic
  Jurassic
  Cretaceous
  Mummiﬁed Edmontosaurus
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  DINOSAURS AND BIRDS
  Scelidosaurus
  The most striking thing about Scelidosaurus was its 
  armor. Rows of bony studs and spikes, some as big  
  as a fist, ran from the head to the tail of this plant  
  eater from the Early Jurassic. The armor probably made 
  Scelidosaurus a slow mover and forced it to walk on four 
  legs rather than two, but speed wasn’t its main defense.
  DID YOU KNOW...?
  Scelidosaurus was discovered in 1858 by 
  James Harrison, an English quarry worker, 
  and was one of the ﬁrst dinosaur skeletons 
  found. Encased in hard limestone that was 
  difﬁcult to remove, the bones were largely 
  hidden from view for more than 100 years. 
  In the 1960s, scientists ﬁgured out how to 
  dissolve the limestone with acid, and the 
  whole skeleton has now been uncovered. 
  251 million years ago
  200
  145
  65
  Triassic
  Jurassic
  Cretaceous
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  DINOSAURS AND BIRDS
   
  ■ When  208–195 million years ago (Early Jurassic) 
   
  ■ Fossil location  England, USA 
   
  ■ Habitat  Woodlands of western Europe and N. America 
   
  ■ Length  12 ft (4 m) 
   
  ■ Diet  Plants 
  All Scelidosaurus fossils have been found in 
  rocks that formed on the seafloor, but this  
  animal wasn’t a sea creature. Perhaps it lived near 
  the coast or perhaps a flood farther inland killed 
  a great number of the dinosaurs and washed 
  them out to sea. A plant-eater, Scelidosaurus 
  probably chomped on low-growing vegetation, 
  shredding leaves with its pointed teeth. It lived 
  in the Early Jurassic and was an early member of 
  a family of dinosaurs known as thyreophorans 
  (“shield bearers,” named for their armor).
  Scelidosaurus
  SKELL-ih-doe-SORE-uss
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  140
  Stegosaurs
  The woodlands of the Jurassic Period teemed 
  with massive, four-legged plant-eaters called 
  stegosaurs. Members of the stegosaur family 
  often had defensive spikes on 
  their tails and shoulders, and 
  rows of bony plates ran along 
  their backs. The purpose of 
  the plates is a mystery, but 
  they may have been used for 
  display or temperature control.
   
  ■ When  150–145 million years ago (Late Jurassic)
   
  ■ Fossil location  USA, Portugal
   
  ■ Habitat  Woodland
   
  ■ Length  30 ft (9 m) 
   
  ■ Diet  Plants 
  Large, diamond-shaped plates ran along  
  the back of this famous dinosaur. 
  Although the plates would have made 
  Stegosaurus look bigger and more 
  fearsome, they were no good as armor. It’s 
  more likely they evolved for use in social or 
  courtship displays. Stegosaurus had a toothless 
  beak made of a hornlike substance. At the 
  back of its mouth were rows of teeth that  
  it used to crush leaves, chewing them to a 
  pulp with simple up-and-down movements.
  Stegosaurus
  STEG-oh-SORE-uss
  Key features
   
  ■ Double row of plates or spikes along 
  the neck, back, and tail 
   
  ■ Narrow head
   
  ■ Beaklike tip of mouth
   
  ■ Hooflike toes
   
  ■ Walked on all fours
  When 
  Stegosaurs lived from 176 million years 
  ago (Middle Jurassic) to 100 million 
  years ago (Early Cretaceous). 
  Each plate was 
  covered with a 
  tough, hornlike 
  layer or skin. 
  The hindlimb 
  was twice as long  
  as the forelimb. 
  d SPIKES 
  Each shoulder had a large spike. 
  Pairs of smaller spikes lined the 
  tail. The spikes probably helped 
  ward off attackers.
  DINOSAURS AND BIRDS
  FAMILY FACT FILE
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  141
  Long jaw had small 
  teeth to chew leaves 
  , POSTURE
  This skeleton gives Stegosaurus 
  an arched appearance, but in 
  reality it probably held its head 
  and tail erect, creating a more 
  horizontal profile.
   
  ■ When  165 million years ago (Middle Jurassic)
   
  ■ Fossil location  China
   
  ■ Habitat  River valleys 
   
  ■ Length  13 ft (4 m) 
   
  ■ Diet   Ferns, leaves, cycad fruit 
  One of the early stegosaurs, Huayangosaurus 
  differed from later species in having a shorter, 
  broader snout, with teeth at the front of its 
  top jaw. All four legs were about the same 
  length, whereas other stegosaurs have  
  long hind legs and short front legs.
  Huayangosaurus
  HWAH-YANG-oh-SORE-uss
   
  ■ When  160–150 million years ago (Late Jurassic)
   
  ■ Fossil location  China
   
  ■ Habitat  Forests
   
  ■ Length  23 ft (7 m) 
   
  ■ Diet  Plants
  Scientists have found remarkably complete 
  fossils of Tuojiangosaurus, a close relative of 
  Stegosaurus that lived in China. The bony 
  plates along its back and hips were tall and 
  triangular, whereas those on its neck were 
  much smaller. Like other stegosaurs, it had 
  vicious spikes at the tip of the tail, allowing  
  it to gore enemies or rivals with a 
  violent lash of the tail.
  Tuojiangosaurus
  TOO-YANG-oh-SORE-uss
  Tail spike 
  for defense 
  DINOSAURS AND BIRDS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  142
  DINOSAURS AND BIRDS
  Kentrosaurus
  Kentrosaurus was a member of the stegosaur family, 
  which lived in what is now central Africa. Its name 
  means “sharp-point lizard”—its shoulders, back, 
  and tail bore fearsome spikes that must have  
  made it difficult for carnivores to attack.
  Out of Africa
  Tendaguru, in the dry woodlands of 
  Tanzania, Africa, is a site famous for 
  fossils of dinosaurs. Two complete 
  skeletons of Kentrosaurus have 
  been assembled from the 900  
  or so bones found there.
  Kentrosaurus’s brain 
  was the size of a walnut. 
  Long tail
  Five-fingered foot
  Rib cage
  u SKELETON 
  Recent research has shown that the posture  
  of Kentrosaurus’s skeleton in many museums 
  is incorrect. It probably held its tail off the 
  ground and did not have sprawling legs.
  251 million years ago
  200
  145
  65
  Triassic
  Jurassic
  Cretaceous
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  143
  The plates of bone on 
  the back may have 
  been used for display.
  Long tail spike
  ONE BRAIN OR TWO?
  Scientists used to think that 
  Kentrosaurus had two brains: 
  a tiny one in its head and 
  a larger one in its rear 
  end. However, experts 
  now think its “rear brain” 
  was just an energy store 
  and not a brain at all.
   
  ■ When  156–150 million years ago (Late Jurassic) 
   
  ■ Fossil location  Tanzania 
   
  ■ Habitat  Forests 
   
  ■ Length  16½ ft (5 m) 
   
  ■ Diet  Plants 
  Seven pairs of plates ran along Kentrosaurus’s neck and back. It had 
  a pair of long spikes on its shoulders to protect itself from side 
  attacks and a series of spikes along its tail to fend off attacks from 
  behind. An entire skull fossil has never been found, but Kentrosaurus 
  probably had a narrow snout and tiny teeth like other stegosaurs.
  Kentrosaurus
  KEN-troh-SORE-uss
  d SPIKED TAIL 
  Carnivores that leaped on Kentrosaurus 
  or that were lashed by its tail risked 
  being stabbed by the tail spikes and 
  suffering fatal injuries.
  DINOSAURS AND BIRDS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  144
  DINOSAURS AND BIRDS
  Ankylosaurs
  Also known as the “armored dinosaurs” or “tank 
  dinosaurs,” the members of this family were built  
  like tanks. Their squat bodies were covered with 
  defensive armor plates and spikes formed from  
  bony growths that developed in the skin. Without 
  this protection, these plant-eaters would have  
  been at the mercy of much swifter and  
  sometimes bigger carnivores.
  Long tail 
  tipped with bony club 
  Soft 
  underbelly
  Bony plates on 
  upper body
   
  ■ When  70–65 million years ago (Late Cretaceous)
   
  ■ Fossil location  N. America
   
  ■ Habitat  Woodlands
   
  ■ Length  20 ft (6 m)
   
  ■ Diet  Low-growing plants
  Ankylosaurus was the largest ankylosaur ever. 
  Hundreds of armor plates studded its thick 
  skin, and small armor plates even covered its 
  FAMILY FACT FILE
  Edmontonia
  ED-mon-TOE-nee-a
  Ankylosaurus
  ANK-ill-oh-SORE-us
  Key features
   
  ■ Heavily armored bodies
   
  ■ Walked on all fours
   
  ■ Horny beak with teeth usually on 
  lower jaw
   
  ■ Some ankylosaurs had tail clubs  
  and horns on the back of the head
   
  ■ Others (known as nodosaurs) had  
  large shoulder spikes
  When
  Ankylosaurs lived during the Jurassic  
  and Cretaceous Periods.
  eyelids. The armor formed from bony plates 
  called osteoderms that grew within the skin, 
  much like the armor plating of a crocodile’s 
  skin. Ankylosaurus was also equipped with a 
  huge tail club that it could swing at attackers 
  with bone-shattering force. 
   
  ■ When  75–65 million years ago (Late Cretaceous)
   
  ■ Fossil location  N. America
   
  ■ Habitat  Woodlands
   
  ■ Length  23 ft (7 m)
   
  ■ Diet  Low-growing plants
  Edmontonia was twice the weight 
  of a rhino and armed with huge 
  spikes jutting out of its shoulders. 
  Perhaps it drove oﬀ attackers by 
  charging and lunging into them, 
  using the spikes as spears. Some 
  scientists think it used its lethal 
  shoulder spikes to ﬁght others of its  
  own kind in battles over territory or mates.
  Shoulder 
  spike
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  145
   
  ■ When  155–145 million years ago (Late Jurassic)
   
  ■ Fossil location  USA
   
  ■ Habitat  Woodlands
   
  ■ Length  13 ft (4 m)
   
  ■ Diet  Low-lying vegetation 
  Gargoyleosaurus had many unusual features for an ankylosaur. 
  Unlike other members of the family, it had teeth at the front  
  of the upper jaw, and its armor plates 
  were hollow. It also had 
  straight nostrils  
  instead of the 
  odd, looping 
  ones seen  
  in other 
  ankylosaurs.
  DINOSAURS AND BIRDS
  Short, sturdy legs
  Spikes on 
  the sides  
  of the body
  Ribs
  Tail bones
   
  ■ When  125 million years ago (Early Cretaceous)
   
  ■ Fossil location  USA
   
  ■ Habitat  Woodlands
   
  ■ Length  13 ft (4 m)
   
  ■ Diet  Plants
  Only the bravest or most desperate predator would risk attacking 
  Gastonia. A walking fortress, it was covered from head to tail with rows 
  of huge, bladelike spikes of bone. It had no tail club, but its spiked tail 
  could swing from side to side to inﬂict savage injuries. The bone forming 
  the top of its skull was dome-shaped and extra thick—perhaps males  
  had head-butting contests over territories or mates.
   
  ■ When  120–115 million years ago (Early Cretaceous)
   
  ■ Fossil location  Australia
   
  ■ Habitat  Scrubby and wooded plains
   
  ■ Length  10 ft (3 m)
   
  ■ Diet  Leaves, seeds, small fruit
  Minmi was one of the smallest of the ankylosaurs. 
  Small, rounded armor plates covered its body, including 
  its belly. Extra bones along its back may have supported  
  its back muscles. Its beak was sharp, and it had small, 
  leaf-shaped teeth with sawtooth edges. Fossilized food remains in 
  the belly of Minmi reveal that it ate leaves, seeds, and small fruits. 
  Gastonia
  gas-TOE-nee-ah
  Gargoyleosaurus
  GAR-goil-oh-SORE-us
  Minmi
  MIN-mee
  Armored shield 
  covering back 
  and tail
  Neck spikes
   
  ■ When  120–110 million years ago 
  (Early Cretaceous)
   
  ■ Fossil location  USA
   
  ■ Habitat  Woodlands
   
  ■ Length  16  ft (5 m)
   
  ■ Diet  Plants 
  Predators risked deadly injury if 
  they tried to bite this dinosaur’s 
  neck, which bristled with vicious, 
  Sauropelta
  SORE-oh-PELT-ah
  hornlike spikes. A thick shield of 
  armor plates covered its back and 
  tail, giving Sauropelta its name 
  (“shield lizard”). The shield was  
  a jigsaw of small plates of bone 
  that ﬁtted together like tiles.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  146
  Euoplocephalus
  One of the largest of the armored dinosaurs (ankylosaurs), 
  Euoplocephalus was twice the size of a rhinoceros and covered 
  in heavy armor. Despite its stocky build and weight, it had 
  powerful legs and may have been quite nimble on its feet. A 
  deadly tail club provided another form of defense for times 
  when its legs or its armor were not enough to save it.
   
  ■ When  70–65 million years ago (Late Cretaceous) 
   
  ■ Fossil location  N. America 
   
  ■ Habitat  Woodlands of N. America 
   
  ■ Length  20 ft (6 m) 
  Euoplocephalus
  YOU-owe-plo-SEFF-ah-luss
  Since its discovery in Canada in 1902, over  
  40 fossils of Euoplocephalus have been found. 
  Some of the skeletons are almost complete, 
  making it the most well-known member of  
  the ankylosaur (armored dinosaur) family. Its 
  armor consisted of plates of bone that mostly 
  grew directly from the skin. In life, the bony 
  plates were covered by a hornlike substance. 
  Some of the plates had a central ridge, giving 
  them a spiked appearance.
  u A TAIL OF DEFENSE
  Euoplocephalus had a heavy tail club that it 
  could swing at attackers with bone-crushing 
  force. But it also had a weak spot: a soft belly, 
  which had no armor.
  , CRAZY PAVING
  Euoplocephalus’s skull 
  was covered with armor plates 
  arranged like paving stones. 
  There were even 
  armored shutters on 
  the eyelids  
  that slid down to 
  protect the eyes.
  d EUOPLOCEPHALUS 
  was the dinosaur 
  equivalent of a Batmobile, 
  with a powerful body, low 
  proﬁle, and heavy-duty 
  armor plating.
  Armored eyelid
  Armor plates on skull
  DINOSAURS AND BIRDS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  147
  251 million years ago
  200
  145
  65
  Triassic
  Jurassic
  Cretaceous
  Hip bone
  Armor plate with 
  central ridge
  Stout, massive arm 
  bones to support the 
  heavy body.
  Broad, beaklike 
  mouth with  
  small teeth
  Armor plates on 
  head
  Hooflike claws
  DINOSAURS AND BIRDS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  148
  DINOSAURS AND BIRDS
  Prosauropods
   
  ■ When  220–210 million years ago (Late Triassic)
   
  ■  Fossil location  Germany, Switzerland, Norway, 
  Greenland
   
  ■ Habitat  Plains of western Europe
   
  ■ Length  25 ft (8 m)
   
  ■ Diet  Plants
  Plateosaurus was one of the largest of the 
  prosauropods. It walked on its hind legs, 
  mainly feeding on plants at ground level. It 
  could also stand like a kangaroo, rearing up on 
  its hindlimbs and stretching its long neck to 
  eat leaves from trees. More than 50 complete 
  skeletons of Plateosaurus have been found. 
  Plateosaurus
  PLATE-ee-oh-SORE-us
  u SCISSOR JAWS 
  Sharp teeth could slice 
  through tough leaf stems.
  Long, curved  
  thumb claw was  
  used for defense  
  and for grasping  
  tree branches. 
  At the start of the Triassic Period, all dinosaurs 
  were small and stood low on the ground. Over 
  time, a group of mainly plant-eating dinosaurs 
  called the prosauropods grew taller and heavier 
  than their competitors. They evolved long 
  necks and tails and strong back legs that 
  allowed them to stand up and  
  reach high tree branches. 
  FAMILY FACT FILE
  Key features
   
  ■ Small heads
   
  ■ Long, flexible necks
   
  ■ Very long thumb claws
   
  ■ Hindlimbs longer than forelimbs 
  When
  Prosauropods first appeared in the  
  Late Triassic, 217 million years ago.  
  They died out in the Middle Jurassic, 
  184 million years ago.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  DINOSAURS AND BIRDS
  , STRONG BODY 
  Muscled hindlimbs helped 
  Massospondylus rear up 
  to feed from trees.
   
  ■ When  225–208 million years ago (Late Triassic)
   
  ■ Fossil location  British Isles
   
  ■ Habitat  Wooded offshore islands of western Europe
   
  ■ Length  7 ft (2 m)
   
  ■ Diet  Plants
  Thecodontosaurus
  THEE-co-DON-toe-SORE-us
   
  ■ When  200–180 million years ago (Early Jurassic)
   
  ■ Fossil location  China 
   
  ■ Habitat  Woodlands of Asia 
   
  ■ Length  20 ft (6 m)
   
  ■ Diet  Plants, including cycad and conifer leaves
  Lufengosaurus was a heavy, stout-limbed dinosaur. 
  Its head was deep and narrow, with bony lumps 
  around its snout and jaws. It used its widely spaced, 
  bladelike teeth to eat tough plants or to nibble  
  on leaves from trees. It may have also eaten small 
  animals. Lufengosaurus probably moved around on 
  two legs most of the time and could rear up to reach 
  higher branches. Its broad hands had long ﬁngers, 
  and each of its thumbs had a massive claw.
  Lufengosaurus
  loo-FENG-oh-SORE-us
   
  ■ When  200–183 million years ago (Early Jurassic)
   
  ■ Fossil location  S. Africa
   
  ■ Habitat  Woodlands of S. Africa
   
  ■ Length  13–20 ft (4–6 m)
   
  ■ Diet  Plants 
  Massospondylus had ﬁve-ﬁngered hands, 
  which it used to grasp and pull down 
  branches. It may also have used its long 
  thumb claws to tear oﬀ pieces of plant 
  material. Small, coarse teeth suggest that it 
  could chew both meat and plants. It may also 
  have swallowed small stones to help digest its 
  food, as many “stomach stones” have been 
  Massospondylus
  MASS-oh-SPON-dill-us
  During World War II, a bomb set ﬁre  
  to the Bristol City Museum in Britain, 
  destroying a precious fossil kept in it. This 
  fossil was of Thecodontosaurus—the 
  oldest dinosaur ever found in Britain. 
  Luckily, some bones were saved and can 
  still be seen in the museum.
  found among its bones. Several 
  complete skeletons and skulls  
  of Massospondylus have been 
  discovered in South Africa. 
  Some eggs containing embryos 
  have also been found. 
  Long tail held out  
  for balance
  Widely spaced  
  teeth could rake 
  leaves oﬀ branches.
  Thecodontosaurus was the ﬁrst prosauropod 
  to be discovered, and was named “socket-
  toothed” after its unusual leaf-shaped, sawlike 
  teeth. Unlike lizards today, whose teeth are 
  fused to their jaw bones, this prosauropod’s 
  teeth were rooted in separate sockets in its  
  jaw bones. As it is smaller than its relatives, 
  scientists think it may have lived on islands, 
  since animals that live on islands are often 
  small in size. Many fossils of Thecodontosaurus 
  have been found in caves, and may have been 
  washed there by rising sea levels. 
  DID YOU KNOW...?
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  Sauropods  
  and relatives
  These lumbering giants were the largest creatures 
  ever to walk the Earth. Amazingly long necks  
  let them reach far higher than other plant eaters 
  could, making it possible to feed on treetops  
  as giraffes do today. But they needed pillarlike 
  limbs to support their immense weight, and, 
  unlike most dinosaurs, they usually had to  
  walk on all fours.
  Brachiosaurus 
  brackee-oh-SORE-uss
   
  ■ When  150–145 million years ago (Late Jurassic) 
   
  ■ Fossil location  USA 
   
  ■ Habitat  Plains
   
  ■ Length  75 ft (23 m)
   
  ■ Diet  Treetop leaves and twigs of conifers
  One of the largest sauropods, Brachiosaurus 
  weighed an incredible 33–55 tons (30–50 
  metric tons)—nearly 12 times more than 
  an African elephant. Brachiosaurus’s long 
  neck helped it to feed at heights of more 
  than 50 ft (15 m), which is twice as high as 
  any giraffe can reach. 
  DINOSAURS AND BIRDS
  FAMILY FACT FILE
  Key features
   
  ■ Small heads and large bodies
   
  ■ Long, flexible necks
   
  ■ Long, whiplike tails
  When
  Sauropods first appeared in the  
  Late Triassic, almost 227 million years 
  ago, and died out at the end of the 
  Cretaceous, 65 million years ago.
  u BRACHIOSAURUS 
  used its spoon-shaped teeth 
  to snip leaves from the tops 
  of conifers, tree ferns, and 
  other trees. It ate about 
  440 lb (200 kg) of leaves 
  and twigs a day.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  151
  u LONG NECK
  Nineteen long  
  bones supported  
  Mamenchisaurus’s 
  neck, which could  
  move freely from side  
  to side. This made it  
  easier for the creature  
  to reach around.
  u LARGE HEAD
  Camarasaurus had 
  a box-shaped head 
  with a blunt snout 
  and huge nostrils. 
   
  ■ When  150–140 million years ago (Late Jurassic) 
   
  ■ Fossil location  USA 
   
  ■ Habitat  Open woodland 
   
  ■ Length  59 ft (18 m)
   
  ■ Diet  Tough tree leaves 
  Numerous Camarasaurus fossils have been found in the United States, 
  making it the best-known sauropod. Its broad and sturdy neck helped 
  it feed on vegetation much lower than that eaten by the larger 
  sauropods. Some of its hollow bones had large air chambers connected 
  to its lungs. These chambers helped reduce body weight and also gave 
  Camarasaurus its name, which means “chambered lizard.” 
   
  ■ When  190 million years ago (Early Jurassic)
   
  ■ Fossil location  USA
   
  ■ Habitat  Woodland
   
  ■ Length  6½ ft (2 m)
   
  ■ Diet  Leaves
  Anchisaurus was a distant cousin of the 
  sauropods. Like most dinosaurs, it walked 
  only on its hindlimbs. It had a narrow snout 
  and fed mainly on plants  
  but may sometimes 
  have eaten small 
  animals too. 
  Camarasaurus
  KAM-a-ra-SORE-uss
  Anchisaurus
  ankee-SORE-uss
  Mamenchisaurus
  ma-MEN-chee-SORE-uss
   
  ■ When  189–176 million years ago (Early Jurassic) 
   
  ■ Fossil location  India 
   
  ■ Habitat  Open woodland 
   
  ■ Length  59 ft (18 m)
   
  ■ Diet   Vegetation
  Barapasaurus probably had a short head. Its neck 
  was supported by a series of long bones and its 
  limbs were slender. Fossils of its teeth show that 
  unlike other sauropods, this creature had 
  sharp teeth with sawlike edges.
  Barapasaurus
  buh-RAH-pah-SORE-uss
  Vulcanodon
  vul-KAN-o-don
   
  ■ When  Early Jurassic 
   
  ■ Fossil location  Zimbabwe
   
  ■ Habitat  Forested plains 
   
  ■ Length  23 ft (7 m) 
   
  ■ Diet  Vegetation
  Vulcanodon was so named because 
  its ﬁrst fossils were found in rocks 
  near volcanoes. Like other sauropods, 
  Vulcanodon moved slowly on land. 
  Its stubby, pillarlike limbs were 
  useful in supporting its heavy body, 
  but were not meant for running. 
   
  ■ When  155–145 million years ago (Middle to Late Jurassic)
   
  ■ Fossil location  China
   
  ■ Habitat  Deltas and forested plains 
   
  ■ Length  85 ft (26 m) 
   
  ■ Diet  Vegetation
  Mamenchisaurus was named after the Chinese 
  village where its fossils were found. It had one of 
  the longest necks of any known animal. Its skull 
  was less pointed than that of Brachiosaurus, and 
  its shoulders were lower and smaller. 
  Strong neck 
  Elephantlike feet
  Huge belly for digesting 
  swallowed leaves
  DINOSAURS AND BIRDS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  152
  Inside a dinosaur
  What was a dinosaur’s anatomy (its insides) like? Was 
  there a diﬀerence in the digestive systems of meat-eaters 
  and plant-eaters? Remarkably, thanks to fossil evidence, 
  we have an idea of what the insides of various dinosaurs 
  would have looked like, as these models show. 
  DINOSAURS AND BIRDS
  Small intestine
  Lung
  Shoulder joint
  Short neck
  PLANTEATER!
  Euoplocephalus lived on tough plants and needed a 
  digestive system that could help break these plants down. 
  This dinosaur could not chew, so instead it mashed its 
  food using small, leaf-shaped cheek teeth, before 
  swallowing. The plant matter went into a gizzard,  
  a churning, muscular stomach, where the 
  plant ﬁbers were broken down.  
  Many modern-day birds and 
  reptiles have a gizzard.
  Wrist joint
  Elbow joint
  Heart
  Liver
  u EUOPLOCEPHALUS was an armored 
  dinosaur (an ankylosaur). These dinosaurs 
  were heavily defended with tough, leathery 
  skin and bony plates (see pages 144–147).
  Gizzard
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  153
  DINOSAURS AND BIRDS
  Strong muscles to 
  support club at 
  end of tail
  Thick, leathery 
  skin
  Thigh muscle
  Spinal bones had a 
  winglike shape
  MEATEATER!
  A meat-eater’s digestive system, 
  shown by this Carnotaurus, was 
  similar to that of reptiles we 
  know today, such as crocodiles. 
  Compared to those of a plant 
  eater, the intestines are small, while the liver 
  is large. The heart and lungs are also large, 
  because the dinosaur would have needed 
  extra oxygen to run after its prey.
  Small arms
  Large intestine
  u CARNOTAURUS Fossils show that 
  many meat-eating dinosaurs had hollows 
  in their bones, which may have been air 
  spaces. These might have allowed an 
  increased oxygen ﬂow to the lungs, 
  helping these dinosaurs to be active.
  Heart
  Small intestine
  Knee joint
  Liver
  Ankle joint
  Short, stumpy legs. 
  These dinosaurs were 
  not built to run
  Stomach
  Lung
  Ankle joint
  Knee joint
  Each toe was tipped 
  with a blunt hoof
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  154
  DINOSAURS AND BIRDS
  251 million years ago
  200
  145
  65
  Triassic
  Jurassic
  Cretaceous
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  155
  DINOSAURS AND BIRDS
  Isanosaurus
  The sauropods were the largest dinosaurs ever to walk on Earth. 
  Some were longer than a blue whale, and the heaviest weighed  
  as much as 12 elephants. Isanosaurus was one of the smaller 
  members of the sauropod family. Like other sauropods, whose 
  fossilized tracks show groups walking together, it might have lived 
  in family groups or herds for safety. It lived during the late Triassic 
  Period, making it one of the earliest known sauropods.
   
  ■ When  216–199 million years ago (Late Triassic) 
   
  ■ Fossil location  Thailand
   
  ■ Habitat  Forests and swamps
   
  ■ Length  40 ft (12 m) 
   
  ■ Diet  Plants
  Isanosaurus was discovered in the Isan 
  region of Thailand. Unfortunately, the 
  remains are incomplete, including only a 
  Isanosaurus
  ee-sahn-oh-SAW-rus
  few back bones, ribs, and a 2 ft (65 cm) 
  long thigh bone. Even so, scientists can  
  tell a lot about Isanosaurus by comparing 
  it to close relatives. It walked on all fours to 
  carry its great weight but it could probably 
  rear up on its back legs to reach high 
  branches. It likely had a small head and 
  spoon-shaped teeth for cropping leaves.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  DINOSAURS AND BIRDS
  Diplodocoids
  The diplodocoids were a group of giant plant-eating 
  dinosaurs that walked on all fours. They had incredibly 
  long necks, balanced by even longer whiplike tails, which 
  they used to lash out at enemies. Their legs were longer 
  at the back than the front, which may have helped them 
  to stand up, using the tail as a prop. One of the largest 
  diplodocoids was Amphicoelias—a dinosaur as long as 
  a football field and as heavy as a blue whale. 
   
  ■ When  150 million years ago (Late Jurassic)
   
  ■ Fossil location  Tanzania
   
  ■ Habitat  Woodlands
   
  ■ Length  39 ft (12 m)
   
  ■ Diet  Plants
  Dicraeosaurus had a shorter neck than other 
  diplodocoids, so it probably fed on bushes 
  rather than trees. Its tail was also shorter, 
  which suggests it wasn’t used like a whip.  
  A layer of skin may have stretched between 
  bony spines that ran along the dinosaur’s neck 
  and back, forming a sail. This perhaps helped  
  to regulate body temperature, or it may have 
  been used for defense or communicating  
  with other members of the species. 
  Dicraeosaurus
  DIE-cray-oh-SORE-us
  FAMILY FACT FILE
  Key features
   
  ■ Long, flexible necks
   
  ■ Long, slender tails
   
  ■ Small heads and large bodies
  When
  Diplodocoids first appeared in the 
  Middle Jurassic, 170 million years ago. 
  They died out at the start of the Late 
  Cretaceous, 99 million years ago. 
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  157
   
  ■ When  150 million years ago (Late Jurassic)
   
  ■ Fossil location  USA
   
  ■ Habitat  Woodlands
   
  ■ Length  75 ft (23 m)
   
  ■ Diet  Plants
  Weighing as much as four elephants, Apatosaurus 
  (or Brontosaurus, as it is popularly known) was 
  shorter and heavier than its relatives, with thicker 
  legs. Some scientists think that instead of rearing up 
  to feed from trees, Apatosaurus may have used its strong 
  limbs and massive weight to knock trees down, as elephants  
  do today. Pencil-like teeth lined the front of its broad muzzle.
  Apatosaurus
  a-PAT-oh-SORE-us
  DINOSAURS AND BIRDS
   
  ■ When  150–145 million years ago (Late Jurassic)
   
  ■ Fossil location  USA
   
  ■ Habitat  Plains
   
  ■ Length  82 ft (25 m)
   
  ■ Diet  Leaves
  Diplodocus is the longest dinosaur known 
  from a complete skeleton. It had an incredibly 
  long tail—as long as the rest of its body—
  which it could move at an amazing speed, 
  creating a whiplike crack. Diplodocus’s neck 
  was almost three times the length of a giraffe’s 
  neck and was probably held up at a high 
  angle. Its backbone was strong enough to 
  Diplodocus
  dip-LOD-oh-kuss
  Amargasaurus
  ah-MAR-gah-SORE-us
   
  ■ When  130 million years ago (Early Cretaceous)
   
  ■ Fossil location  Argentina
   
  ■ Habitat  Woodlands
   
  ■ Length  36 ft (11 m)
   
  ■ Diet  Plants
  This relatively small and short-necked 
  diplodocoid was unusual because it had 
  a double row of spines running along its 
  neck and back that became a single line 
  down its tail. There may have been a web  
  of skin running between the spines, forming  
  a double sail. Why it had a sail on its back is  
  a mystery, but perhaps Amargasaurus used it 
  for display. Some scientists think it didn’t  
  have a sail and simply rattled the spines  
  to make a noise.
  support its enormous weight, but the bones 
  were hollow. Some scientists think it was a 
  tree-browser, using the peglike teeth at the 
  front of its jaws to strip leaves off branches. 
  Others think it couldn’t lift its head high 
  enough and probably swung it from side to 
  side to browse on low shrubs. Diplodocus may 
  have grown at a very fast rate, taking around 
  10 years to become  
  a full-sized adult.
  u BONY BRIDGE To support its long neck 
  and tail, Diplodocus’s backbone acted like the 
  cables in a suspension bridge. The cables take 
  the weight of the road (the neck 
  and tail) and pass it down 
  through the piers (the legs), 
  which anchor it to the ground.
  d GIANT FOOTPRINTS 
  The Morrison Formation 
  in the US has revealed 
  many bones and footprints 
  of giant diplodocoids such as 
  Apatosaurus and Diplodocus, 
  along with fossils of the trees  and 
  plants they ate.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  158
   
  ■ When  155–145 million years ago (Late Jurassic) 
   
  ■ Fossil location  USA
   
  ■ Habitat  Plains of N. America
   
  ■ Length  92 ft (28 m)
   
  ■ Diet  Plants
  The first Barosaurus remains were found 
  during the “Bone Wars” of the late 1800s, 
  when a number of fossil hunters raced to 
  out-do each other with new dinosaur fossil 
  discoveries. In 1922, three Barosaurus 
  skeletons were found at Carnegie Quarry  
  in Utah, suggesting that Barosaurus may 
  have roamed in herds.
  Barosaurus
  BAH-roe-SORE-us
  Feeding on stones 
  Barosaurus’s large peglike teeth were 
  perfect for pulling leaves off trees, but  
  not for chewing them. Some scientists 
  thought it swallowed stones to help grind 
  food in its stomach, but recent research 
  has shown that it used bacteria in its gut 
  to digest food.
  Sticking its neck out? 
  In 1993, a model Barosaurus was mounted 
  rearing on its hind legs. Some scientists 
  think this position is incorrect—the heart 
  could not have been strong enough to pump 
  blood vertically upward to the brain. New 
  research suggests that with the right-sized 
  heart, this is indeed possible.
  Spiny back
  No one is sure why Barosaurus had 
  spines running along its back—they 
  may have been used for defense, or may 
  simply have been a decorative feature. 
  These spines were bony plates fixed in 
  the skin and were not attached to the 
  skeleton. Barosaurus’s rough, scaly skin 
  gave it much needed protection against 
  scratches and bite wounds. It also helped 
  reduce moisture loss from its body when 
  the climate turned dry.
  DINOSAURS AND BIRDS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  159
  Barosaurus
  Barosaurus must have made an impressive sight as 
  it browsed its way through the Jurassic forests. This 
  dinosaur had all the usual sauropod features—a  
  bulky body, tiny head, and relatively short legs.  
  It was heavier than three elephants and longer 
  than a tennis court. But what really gave it 
  an advantage over other plant eaters was 
  its 30 ft (9.5 m) neck, which allowed  
  it to reach leaves right at the tops  
  of the trees. 
  251 million years ago
  200
  145
  65
  Triassic
  Jurassic
  Cretaceous
  DINOSAURS AND BIRDS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  160
  Building a dinosaur
  At the American Museum of Natural History in 
  New York City, a Barosaurus mother rears up on 
  her hind legs to drive a predatory Allosaurus away 
  from her calf. These fossils may look real, but, in 
  fact, they are lightweight replicas. Reconstructing 
  dinosaur fossils for display in museums is a 
  complicated but fascinating task requiring many 
  diﬀerent skills and a lot of careful preparation.
  u Careful planning is essential 
  before the skeleton is constructed. 
  Every bone is labeled and marked 
  on a plan to show where it belongs.
  u Here the ribs of the Barosaurus are joined 
  to part of its backbone. The backbone is 
  supported by a metal frame.
  u The hind legs and pelvis (hip 
  bones) are lowered into position in 
  the museum by a small crane. 
  u The skeleton of the 
  attacking Allosaurus is 
  also assembled. It will face 
  Barosaurus in the display.
  DINOSAURS AND BIRDS
  PUTTING TOGETHER A DINOSAUR
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  161
  u A welder joins every part of the 
  Barosaurus to the metal frame 
  inserted in its skeleton.
  u The ﬁnal stage is to join 
  Barosaurus’s upper neck and 
  head to its lower neck.
  u STEP 1 The fossil is ﬁrst pressed 
  halfway into a clay base, and liquid 
  rubber (shown in blue) is painted 
  over both the fossil and the base. 
  This will set to form a ﬂexible coat.
  u STEP 2 Once dry, the rubber 
  is covered with ﬁberglass sheets. 
  The sheets make the rubber mold 
  rigid enough to keep its shape 
  when it is removed.
  u STEP 3 Once set, the outer 
  mold is removed. Now a second 
  mold is made in the same way of 
  the other side of the fossil.
  u STEP 4 The two molds are 
  joined and held together.
  u STEP 5 The complete mold is 
  ﬁlled with liquid polyester or 
  some other lightweight material. 
  This will form a cast.
  u STEP 6 Finally, the mold can 
  be opened gently. If the 
  technicians have been careful,  
  a perfect cast is revealed.
  DINOSAURS AND BIRDS
  MAKING A REPLICA OF A DINOSAUR
  There are diﬀerent methods of making a replica of  
  a dinosaur’s fossilized skeleton. One way is to make  
  a mold of each fossilized bone and use these molds  
  to make a cast.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  162
  DINOSAURS AND BIRDS
  Titanosaurs
  Named after the Titans, a race of giants in Greek 
  mythology, titanosaurs were among the heaviest animals 
  ever to walk on Earth. They were also among the last of 
  the dinosaurs. Titanosaurs were plant eaters and probably 
  lived in herds to protect themselves against predators. 
  The discovery of thousands of eggs scattered across a vast 
  area in Argentina suggests that they also nested together.
   
  ■ When  80–65 million years ago (Late Cretaceous)
   
  ■ Fossil location  Mongolia
   
  ■ Habitat  Woodlands
   
  ■ Length  50 ft (15 m)
   
  ■ Diet  Plants
  Nemegtosaurus was named after the Nemegt Basin—in the Gobi 
  Desert of Mongolia—where it was first discovered. Only its skull 
  was found, which shows that it may have had a sloping head and 
  small, peg-shaped teeth at the front of its jaws. Like 
  most other titanosaurs, its neck was 
  probably long and flexible, 
  allowing it to feed  
  on high tree 
  branches.
  Nemegtosaurus
  nem-EGG-toe-SORE-us
  Key features
   
  ■ Small, wide heads and flexible necks
   
  ■ Small teeth
   
  ■ Long tails, but shorter than diplodocoids
   
  ■ Walked on all four legs
   
  ■ Many had tough armor plates of bone 
  covering their bodies
  When
  Titanosaurs first appeared in the  
  Middle Jurassic, 168 million years ago. 
  They died out in the Late Cretaceous,  
  65 million years ago. They were first 
  thought to be restricted to the southern 
  hemisphere, but are now known to  
  have been more widespread.
  FAMILY FACT FILE
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  DINOSAURS AND BIRDS
   
  ■ When  112–95 million years ago (Late Cretaceous)
   
  ■ Fossil location  Argentina
   
  ■ Habitat  Forested areas
   
  ■ Length  100 ft (30 m)
   
  ■ Diet  Conifers
  Argentinosaurus was one of the largest and 
  heaviest land animals ever. Only a few bones 
  have been found, including some enormous,  
  6 ft (1.8 m) tall spine bones. By comparing 
  these to other sauropods, scientists have 
  calculated that Argentinosaurus was longer 
   
  ■ When  80–65 million 
  years ago (Late Cretaceous)
   
  ■ Fossil location  Asia, Europe, Africa
   
  ■ Habitat  Woodlands
   
  ■ Diet  Plants
  Titanosaurus is something of a mystery. Even 
  though discovery of its tail bones led to a 
  whole family of dinosaurs being named after 
  it, it is probably a case of mistaken identity. 
   
  ■ When  70–65 million years ago (Late Cretaceous)
   
  ■ Fossil location  Asia
   
  ■ Habitat  Woodlands
   
  ■ Length  60 ft (18 m)
   
  ■ Diet  Plants
  With its long front legs and shorter 
  neck, Isisaurus differed from other 
  titanosaurs by standing more like a 
  hyena. Its fossilized dung contained fungi 
  found on many types of leaf. This suggests 
  that it sampled leaves from different trees.
  Argentinosaurus
  ARE-jen-teen-oh-SORE-us
  Titanosaurus
  tie-TAN-oh-SORE-us
  Isisaurus
  ISS-ee-SORE-us
  than a tennis 
  court and nearly 
  20 times heavier than 
  an elephant. Its eggs were 
  the size of footballs, so  
  it probably took around  
  40 years to reach adult  
  size. Despite its massive 
  size, it was hunted by 
  Mapusaurus, a giant 
  flesh-eating dinosaur.
   
  ■ When  80–65 million years ago (Late Cretaceous)
   
  ■ Fossil location  Argentina
   
  ■ Habitat  Woodlands
   
  ■ Length  40 ft (12 m)
   
  ■ Diet  Plants
  This relatively small titanosaur was well protected against 
  attack. Large predators couldn’t rip open its thick armored 
  hide, which had plates and studs made of bone. Its strong 
  hips and wide upper-tail bones suggest that it may have been 
  able to stand on its hind legs, using its tail to prop itself up. 
  However, Saltasaurus had no toes or claws on its front feet.
  Saltasaurus
  SALT-ah-SORE-us
  The features that 
  once marked it out 
  as a unique species have 
  since been found in other 
  titanosaurs. Without a 
  full skull and skeleton to examine, it is hard  
  to say whether the species actually existed.
  Thick limbs with 
  clawed toes
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  164
  DINOSAURS AND BIRDS
  Dinosaur tracks
  About 190 million years ago, a large predatory dinosaur was 
  walking along the shore of a river when it suddenly stopped 
  in its tracks. It turned, and then broke into a run, perhaps in 
  a dash for prey. How do we know this? Because its footprints 
  became fossilized. Dinosaur tracks can give us an amazing 
  glimpse into the behavior of the animals that left them.
  u THIS PRINT is one 
  of about 2,000 that were 
  found at Dinosaur State 
  Park in Connecticut. No 
  remains of the dinosaurs were 
  found, but scientists think they 
  may have been Dilophosaurus or 
  something similar. The animals 
  seem to have been crossing an 
  ancient mudﬂat.
  This set of tracks was found 
  in Spain. The prints are 
  nearly 3 ft (1 m) apart, 
  suggesting a big animal  
  made them. The shape of 
  the foot indicates it was a 
  theropod (a meat-eater).
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  165
  DINOSAURS AND BIRDS
  TRACKING DINOSAURS
  Dinosaur footprints that form a long trail 
  are rare but give us fascinating clues about 
  the way dinosaurs lived. Most tracks do not 
  show drag marks left by the tail, telling us 
  that dinosaurs held their tails up. Parallel 
  tracks (tracks that run side by side) show 
  that some species traveled in herds. 
  u SAUROPOD TRACKS A group of ﬁve 
  sauropods appear to have left these tracks. The 
  narrow paths show that the dinosaurs walked 
  with limbs held straight, rather than splayed  
  like the legs of crocodiles. 
  Why are they on a cliff face?
  The dinosaurs that left these tracks were walking 
  along a sandy shore or a mudﬂat. Later, the prints 
  became buried and the mud or sand turned to rock. 
  Movements in Earth’s crust have since tilted the 
  layer of rock, so the prints now run vertically.
  , A LONG TRACKWAY 
  The world’s longest dinosaur 
  trackway is found on a cliﬀ 
  face in Bolivia, South 
  America. The tracks are  
  those of a titanosaur.
  POSITIVE OR NEGATIVE?
  Fossil footprints can be positive  
  or negative. Positive prints are simply 
  impressions in rock and look like 
  ordinary footprints. Negative prints 
  look like the underside of a dinosaur 
  foot, as though viewed from below.  
  They form when a footprint ﬁlls with  
  sand to form a natural cast. Millions  
  of years later, the sandstone cast is  
  all that is left behind.
  , POSITIVE 
  These tracks look like 
  ordinary footprints.
  . NEGATIVE 
  These tracks look like the 
  bottom of a dinosaur’s foot. 
  DID YOU KNOW?
  The 100 million-year-old dinosaur footprint 
  below was found on a beach in Portugal. It was 
  made by an iguanodontian—a plant-eater. The 
  dinosaur was walking on its own and its tracks 
  cross those of two meat-eating dinosaurs.
  u AT OLHOS DE AGUA, Portugal, this 
  huge iguanodontian footprint was found.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  Theropods
  Theropods were the world’s top predators throughout 
  much of the dinosaurs’ reign. This branch of the 
  dinosaur family tree gave rise to some truly gigantic 
  carnivores (although not all were meat-eaters). A 
  selection of these immense animals is shown here. 
  Interestingly, one group of theropods would evolve  
  into the birds that share our world today.
  DINOSAURS AND BIRDS
  Key features 
   
  ■  Long skulls with large eye sockets, and 
  often horns or crests on top 
   
  ■ Air-filled bones
   
  ■  Many had a furcula, or wishbone. 
  Birds today have this feature.
   
  ■ Immense jaws with curved teeth
   
  ■ Strong arms with three-fingered hands
   
  ■ Three-toed feet
  When
  Theropods flourished from the  
  Late Triassic to the Late Cretaceous 
  (230–65 million years ago).
  FAMILY FACT FILE
  u THEROPODS walked 
  on immense hind legs, using a 
  stiﬀ, muscular tail to balance 
  the great weight of a massive 
  head and fang-lined jaws. 
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  167
   
  ■ When  Late Cretaceous 
   
  ■ Fossil location North Africa 
   
  ■ Habitat  Floodplains and mangroves 
   
  ■ Size  39–43 ft (12–13 m) long  
  Carcharodontosaurus was one of the biggest 
  carnivorous dinosaurs ever. This monster  
  was twice the weight of an elephant and  
  had massive jaws equipped with teeth  
  8 in (20 cm) long. Its name means “shark-
  toothed lizard”—it was named for the rough 
  similarity once observed between its teeth and 
  those of Carcharodon, the great white shark.
  Carcharodontosaurus
  CAR-ka-roe-DON-toe-sore-us
   
  ■ When  Late Cretaceous
   
  ■ Fossil location Argentina
   
  ■ Habitat  Woodlands
   
  ■ Size  39 ft (12 m) long
  Giganotosaurus was a formidable predator—it 
  was as heavy as 125 people. It was more than 
  capable of preying on the giant sauropods  
  that roamed South America in the  
  late Cretaceous.
  Giganotosaurus
  gig-AN-oh-toe-SORE-rus
   
  ■ When  Middle Jurassic 
   
  ■ Fossil location China
   
  ■ Habitat  Woodlands 
   
  ■ Size  20 ft (6 m) long  
  Monolophosaurus had a 
  thick and bumpy head 
  crest. This was hollow and 
  may have acted as a means for the 
  dinosaur to produce loud noises, possibly 
  to attract a mate or to warn oﬀ a rival.  
  It had a particularly slender lower jaw,  
  but enormous nostril openings.
  Monolophosaurus
  MON-oh-LOAF-oh-SORE-rus
   
  ■ When  Middle Jurassic 
   
  ■ Fossil location  China 
   
  ■ Habitat  Woodlands 
   
  ■ Size  11½ ft (3.5 m) long  
  Just a few of this dinosaur’s 
  bones were discovered accidentally 
  in 1985 when a Chinese gas-mining company 
  was using dynamite to clear rocks. This 
  unusual means of its discovery is reﬂected in 
  its name, which means “gas lizard.” No skull 
  has ever been found, so its proposed shape is 
  based on other similar dinosaurs.
  Gasosaurus
  GASS-oh-sore-us  
   
  ■ When  Late Jurassic 
   
  ■ Fossil location China
   
  ■ Habitat  Woodlands 
   
  ■ Size  25 ft (7.5 m) long 
  “Sinraptor” means “Chinese hunter.” Scientists have found tooth 
  marks on a Sinraptor’s skull that seem to have been made by another 
  Sinraptor, which suggests that these dinosaurs may have engaged 
  in vicious ﬁghts.
  Sinraptor
  SIN-rap-tor
  u SINRAPTOR was a 
  close relative of Allosaurus 
  (see pages 178–179).
  . THIS dinosaur 
  was probably 
  reasonably agile.
  DINOSAURS AND BIRDS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  168
  Eoraptor
  Eoraptor was one of the earliest dinosaurs. 
  Its name means “dawn thief” in recognition of  
  its place at the dawn of the dinosaur era. About 
  the size of a fox, Eoraptor stood and ran quickly 
  on its two hind legs. It killed prey by using  
  its claws and teeth to tear the victim apart.  
   
  ■ When  230–225 million years ago (Middle Triassic)
   
  ■ Fossil location  Argentina
   
  ■ Habitat  River valleys
   
  ■ Length  3 ft (1 m)
   
  ■ Diet  Lizards, small reptiles, sometimes plants
  Only one complete fossil skeleton of Eoraptor 
  has been found so far, but it reveals much 
  about early dinosaurs. Eoraptor had primitive 
  features, including ﬁve ﬁngers on its front 
  limbs, weak claws, and lizardlike hips. 
  Scientists are not sure whether it had scales  
  or feathers. Eoraptor is thought to have been  
  a ﬁerce and quick-witted hunter.
  Eoraptor
  EE-oh-rap-tor
  DINOSAURS AND BIRDS
  Moon reptile
  The ﬁrst Eoraptor fossils were 
  discovered in 1991 in the Valley of  
  the Moon, a region in northwestern 
  Argentina. It is a barren landscape of 
  bare rock, and looks like the surface  
  of the Moon. When Eoraptor lived 
  there in the Late Triassic the area 
  was a lush river valley. 
  Strong thigh bones and 
  muscles helped Eoraptor 
  to stand upright.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  169
  u JAWS Eoraptor had the bladelike teeth of a 
  carnivore—suitable for slicing through meat. It 
  mainly hunted small animals, but may have 
  taken on bigger prey by tearing out lumps of 
  ﬂesh and waiting for its victim to weaken.
  DINOSAURS AND BIRDS
  Eoraptor only had claws on the 
  three longest ﬁngers of its hands. 
  The other two ﬁngers were 
  shorter but probably helped  
  when searching through 
  vegetation for prey.
  The mouth was full of 
  sawlike teeth, ideal for  
  slicing through ﬂesh. Some 
  scientists think Eoraptor 
  may have eaten plants too.
  . BECAUSE Eoraptor’s eyes were 
  set on the side of its head, it 
  couldn’t see straight ahead 
  well, but it did have 
  a good all- 
  around view. 
  Eoraptor had a shorter neck 
  than the later carnivorous 
  dinosaurs, but its neck was 
  ﬂexible enough for snatching 
  prey from the ground.
  251 million years ago
  200
  145
  65
  Triassic
  Jurassic
  Cretaceous
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  Coelophysis
  One of the earliest theropods, Coelophysis was a small 
  and nimble, birdlike carnivore that darted after prey  
  in the riverside forests of the Triassic Period, snapping  
  up small lizards. It was built for speed, with lightweight, 
  hollow bones and a slender frame. In 1998 a Coelophysis 
  skull was taken on board space shuttle Endeavour, making 
  it the second dinosaur (after Maiasaura) to visit space.
  Coelophysis had a long, flexible neck 
  that formed an S-shape when relaxed, like 
  the neck of a heron. By straightening its 
  neck quickly, it could dart for fast-moving 
  prey on the ground. 
  Coelophysis had hundreds 
  of small, sharp teeth. They 
  had sawtooth edges—a  
  sign that it ate flesh.
   
  ■ When  215 million years ago (Late Triassic)
   
  ■ Fossil location  N. America, southern Africa, China
   
  ■ Habitat  Desert plains
   
  ■ Length  10 ft (3 m)
   
  ■ Diet  Lizards and ﬁsh
  Coelophysis was as long as a small car but 
  as light as an 8-year-old child. With a long, 
  curved neck and slender legs, it resembled  
  a long-legged bird. In 1947 scientists made  
  an amazing discovery of 500 Coelophysis 
  skeletons piled together at Ghost Ranch in 
  New Mexico—a Coelophysis “graveyard.” 
  They seem to have died together, perhaps 
  victims of a sudden flood. The find inspired 
  stories of Coelophysis hunting in huge packs 
  to overpower large prey, but there is no 
  evidence this happened.
  Coelophysis
  SEE-low-FYE-sis
  DINOSAURS AND BIRDS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  d CANNIBALISM Tiny bones in the stomach 
  of this fossilized Coelophysis were once thought 
  to be those of a baby Coelophysis and 
  a sign of cannibalism. However, 
  some experts now think  
  the bones were those  
  of other reptiles that 
  Coelophysis hunted.
  251 million years ago
  200
  145
  65
  Triassic
  Jurassic
  Cretaceous
  DINOSAURS AND BIRDS
  The tail was long and stiff. It acted like 
  a rudder, helping Coelophysis balance 
  when running after prey or fleeing from 
  bigger carnivores.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  DINOSAURS AND BIRDS
  Dubreuillosaurus
  Prowling through the coastal swamps of the Jurassic 
  Period was the carnivorous predator Dubreuillosaurus. 
  Like its relative Spinosaurus, it may have been a fish 
  hunter that specialized in snatching slippery prey from 
  shallow waters with its pointed, fang-filled snout.
   
  ■ When  170 million years ago (Middle Jurassic)
   
  ■ Fossil location  France
   
  ■ Habitat  Mangrove swamps
   
  ■ Length  20 ft (6 m)
   
  ■ Diet  Fish and other marine animals
  Little is known about Dubreuillosaurus, since only 
  a single partial skeleton has been found. It had an 
  unusually long and shallow skull, which was three 
  times as long as it was deep. The skull did not have 
  any distinct crests or horns, like those seen on other 
  dinosaur skulls, but since the only known specimen 
  is a young Dubreuillosaurus, these structures may 
  have developed in adults.
  Dubreuillosaurus
  doo-BRAY-oh-sore-us
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  DINOSAURS AND BIRDS
  Mistaken identity
  251 million years ago
  200
  145
  65
  Triassic
  Jurassic
  Cretaceous
  Dubreuillosaurus was named in 2002 
  and was originally thought to be a new  
  species of Poekilopleuron, a large allosaur-like 
  theropod. Later study of its hollow skull 
  showed Dubreuillosaurus was more closely 
  related to the megalosaurids. Like its 
  relatives, it probably had short, 
  powerful arms with three-fingered 
  hands, heavily muscled legs, and 
  a stiff tail that it held out 
  for balance. 
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  174
  DINOSAURS AND BIRDS
  Spinosaurids
  Spinosaurids were huge, sail-backed dinosaurs 
  that lived in swamps and estuaries. With  
  their crocodile-like snouts and powerful 
  clawed hands, they were ideally built 
  for catching the monster  
  fish of the time. They 
  were also skilled at 
  hunting on land.
   
  ■ When  110 million years ago (Early Cretaceous)
   
  ■ Fossil location  Brazil
   
  ■ Habitat  Lakesides
   
  ■ Length  26 ft (8 m)
   
  ■ Diet  Meat and ﬁsh
  In 1996 this spinosaurid’s long, crocodile-like 
  skull was discovered in Brazil by a fossil hunter.  
  Its name is the result of a clumsy attempt to 
  mend the snout with plaster, which irritated 
  the scientists who tried to undo the damage. In 
  addition to a sail along its back, it may also 
  have had a small crest on the back of its head.
  Irritator
  IH-rih-tay-tore
   
  ■ When  97 million years ago (Late Cretaceous)
   
  ■ Fossil location  Morocco, Libya, Egypt
   
  ■ Habitat  Tropical swamps
   
  ■ Length  60 ft (18 m)
   
  ■ Diet  Fish and other animals
  Even bigger than Tyrannosaurus, Spinosaurus 
  was the largest land-dwelling predator of all 
  time. What made it spectacular was an 
  enormous “sail” running along its back. This 
  was supported by spines made of bone, which  
  were as tall as a man—giving it the name 
  Spinosaurus, meaning “spine lizard.” It may 
  have hunted on land and in water, just like 
  crocodiles today. It probably ate smaller 
  dinosaurs, turtles, and birds, as well as fish.
  Spinosaurus
  SPINE-oh-SORE-us
  Short, raised 
  toe at the back 
  of the foot
  Powerful 
  hind leg
  u LONG TEETH 
  Irritator used its long 
  teeth to grab and hold  
  on to fish. It may have  
  fed on dead meat and 
  land animals, too.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  175
  DINOSAURS AND BIRDS
  u CURVED CLAW 
  Baryonyx means “heavy claw,” 
  referring to its huge, hooklike 
  thumb claws, which it may  
  have used to spear fish, as  
  grizzly bears do today. 
   
  ■ When  125 million years ago (Early Cretaceous)
   
  ■ Fossil location  British Isles, Spain, Portugal
   
  ■ Habitat  Riverbanks
   
  ■ Length  30 ft (9 m)
   
  ■ Diet  Fish and meat
  Remains of partly digested dinosaurs were 
  found in Baryonyx’s fossilized stomach, 
  indicating that it ate land animals as well as fish. 
  It had a very long, low skull, and its jaws had 96 
  pointed teeth—twice as many as other members 
  of its family. Baryonyx may have had a ridge on 
  its back and a small crest on its snout.
  Baryonyx
  bah-ree-ON-ix
  Smooth sailing
  Spinosaurus’s sail might have had various uses. 
  Some scientists think it was for display or that  
  it acted as a radiator, helping Spinosaurus 
  to keep cool in the hot climate. Others think 
  the sail was a hump that stored body fat for 
  energy, as in modern camels.
  FAMILY FACT FILE
  Key features
   
  ■ Crocodile-like heads and snouts
   
  ■ Big conical teeth 
   
  ■ Large sail on back
   
  ■ Stiff tails, held out for balance
  When
  Spinosaurids first appeared in the  
  Late Jurassic, 155 million years ago. 
  They died out in the Late Cretaceous, 
  93 million years ago, when sea levels 
  dropped on Earth and the swamps  
  that spinosaurids lived in dried up.
  Nostrils set back from the tip of 
  the snout enabled spinosaurids 
  to breathe while fishing.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  176
  DINOSAURS AND BIRDS
  Suchomimus
  One of the spinosaurids that stalked the lush 
  Cretaceous swamps was Suchomimus. 
  It was as big as Tyrannosaurus 
  but hunted fish. Suchomimus 
  probably stood in water 
  watching for passing fish, 
  which it then snapped  
  up in its huge mouth or 
  speared with its thumb 
  claws. With its long 
  jaws and sharp teeth,  
  it was the perfect 
  swamp predator.
   
  ■ When  112 million years ago (Early Cretaceous)
   
  ■ Fossil location  Africa
   
  ■ Habitat  Mangrove swamps
   
  ■ Length  30 ft (9 m)
   
  ■ Diet  Fish, possibly meat
  Suchomimus, meaning “crocodile mimic,” got its 
  name from its crocodile-like snout and sharp teeth, 
  which it used to catch fish and other slippery prey. 
  Compared to other meat eaters, it had long and 
  powerful arms—perhaps it used them to reach into 
  the water to grasp prey. A bladelike sail ran along 
  its back and perhaps its tail.
  Suchomimus
  soo-ko-MIME-us
  , TOOTHY CREATURE Suchomimus 
  had more than 100 teeth along its jaw that 
  slanted backward and were pointed like  
  the prongs of a rake. Another set of 
  longer teeth lay clustered at  
  the tip of its snout.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  177
  DINOSAURS AND BIRDS
  Desert find
  In 1997, scientists found a nearly complete Suchomimus skeleton in 
  the Sahara Desert. The bones had been partly exposed by wind, but 
  removing them meant shifting 16½ tons (15 metric tons) of rock and 
  sand. One of the first things they saw was a huge, sickle-shaped claw. 
  251 million years ago
  200
  145
  65
  Triassic
  Jurassic
  Cretaceous
  Breathing easy
  Suchomimus’s nostrils were set a long 
  way back from the tip of its snout. 
  This allowed it to breathe while 
  feeding in water or when 
  scavenging inside the body 
  of a dead dinosaur. 
  Suchomimus’s discoverers Rod Sadleir and Paul Sereno in the Sahara.
  Sereno excavates a bone.
  Suchomimus’s thumb claw is longer than a human hand.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  178
  Allosaurus
  One of the best-known of the giant flesh-eating 
  dinosaurs of the Jurassic Period was Allosaurus. 
  This animal resembled Tyrannosaurus, the monster 
  dinosaur that would appear 70 million years later.  
  Since fossil footprints of several Allosaurus have been 
  found together, some scientists believe these animals may 
  have hunted in packs to bring down much bigger game. 
  Others think that large allosaurs may have killed and eaten 
  smaller individuals that tried to muscle in on their dinner.
  DINOSAURS AND BIRDS
  251 million years ago
  200
  145
  65
  Triassic
  Jurassic
  Cretaceous
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  179
  Triangular horns in 
  front of each eye, 
  perhaps for display
   
  ■ When  150 million years ago (Late Jurassic)
   
  ■ Fossil location  USA, Portugal
   
  ■ Habitat  Plains
   
  ■ Length  39 ft (12 m)
   
  ■ Diet  Meat 
  When young, Allosaurus was a fast 
  runner and probably actively chased after 
  prey, sprinting on its long and powerful 
  hindlimbs. Older individuals were heavier 
  and probably relied more on ambushing 
  victims than running them down. The 
  long, curved claws on the hands were 
  used like meat hooks to capture prey.  
  As well as hunting, Allosaurus may have 
  also scavenged on dead animals.
  d HOLEY SKULL The massive 
  skull had large openings that made  
  it lightweight, yet strong. The bone  
  was also riddled with smaller holes  
  that may have contained air sacs  
  linked to the lungs.
  Allosaurus
  al-oh-SORE-us
  Tail held 
  outstretched  
  for balance
  DINOSAURS AND BIRDS
  Teeth had serrated 
  edges like a saw
  Deep and 
  narrow jaw
  KILLER TEETH 
  Although Allosaurus was a fierce 
  predator, scientists think it had a 
  rather weak jaw that prevented it 
  from crunching bones. Its teeth  
  were like saw blades and could slice 
  through skin and muscle to tear  
  out great ribbons of flesh. Victims 
  that managed to escape after being 
  attacked would probably have  
  bled to death.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  DINOSAURS AND BIRDS
  Tyrannosauroids
  Among the largest and most terrifying predators of all 
  time were the tyrannosauroids (“tyrant lizards”). The first 
  tyrannosauroids were small, possibly feathered dinosaurs, 
  but over millions of years they evolved into giants, the 
  biggest being Tyrannosaurus (next page). The giant 
  tyrannosauroids had immensely powerful 
  jaws lined with bone-crunching fangs, 
  equipping them to butcher and 
  consume almost any 
  animal they came across.
  Tarbosaurus
  TAR-bow-SORE-us
   
  ■ When  70–65 million years ago (Late Cretaceous)
   
  ■ Fossil location  Mongolia, China
   
  ■ Habitat  Floodplains
   
  ■ Length  39 ft (12 m)
   
  ■ Diet  Flesh
  While Tyrannosaurus was terrorizing the wildlife of North America, 
  its close relative Tarbosaurus was doing the same in China. 
  Tarbosaurus was almost as big as its cousin but had a more slender 
  skull and even tinier arms. It probably used the same feeding 
  technique, crushing victims in its jaws and then tearing off  
  chunks of flesh while holding the carcass down with its feet.
  FAMILY FACT FILE
  Key features
   
  ■ Large skull and jaws relative to body size
   
  ■ Small but powerful arms with only two 
  or three fingers on each hand
   
  ■ Long back legs built for running
  When
  Tyrannosauroids appeared in the Jurassic 
  Period, 200 million years ago and died 
  out at the end of the Cretaceous Period, 
  65 million years ago.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  181
  DINOSAURS AND BIRDS
   
  ■  When  75 million years ago 
  (Late Cretaceous)
   
  ■ Fossil location  Canada
   
  ■ Habitat  Forests
   
  ■ Length  30 ft (9 m)
   
  ■ Diet  Flesh
  Albertosaurus was more lightly built than 
  the largest tyrannosauroids, suggesting it 
  was a swift runner. Its head was huge, with 
  triangular horns in front of the eyes, and its 
  jaws were lined with 60 banana-shaped teeth. More 
  than 30 specimens of Albertosaurus have been found, 
  including 22 at a single site that contained a mix of old 
  and young individuals. Some experts think the mass 
  grave is evidence that Albertosaurus lived and hunted 
  in packs. The species was named after Alberta in 
  Canada, where it was first discovered.
   
  ■ When  160 million years ago (Late Jurassic)
   
  ■ Fossil location  China
   
  ■ Habitat  Woodlands
   
  ■ Length  8 ft (2.5 m)
   
  ■ Diet  Flesh
  Guanlong was discovered in China in 1996. Its name means 
  “crowned dragon” in Chinese and refers to a hollow crest on 
  the skull, running from the nose to the back of its head. The 
  crest was probably used in display, perhaps helping to 
  attract mates. An early tyrannosauroid, Guanlong 
  was much smaller than the later giants and 
  had three fingers on each hand rather 
  than two. It was a close relative of 
  early feathered dinosaurs 
  and may well have had 
  a coat of fuzzy 
  feathers itself.
  Albertosaurus
  al-BERT-oh-SORE-us
  Guanlong
  GWON-long
   
  ■ When  175 million years ago (Middle Jurassic)
   
  ■ Fossil location  British Isles
   
  ■ Habitat  Open woodland
   
  ■ Length  6 ft (2 m)
   
  ■ Diet  Flesh
  The only fossil of Proceratosaurus is a 
  remarkably well-preserved skull found in 
  England in 1910. The dinosaur is thought  
  to be a small, early tyrannosauroid and a  
  close relative of Guanlong (below). Its most 
  Proceratosaurus
  PRO-seh-RAT-oh-SORE-us
  distinctive feature is a 
  strange crest perched on 
  the tip of its snout. 
  Because the top of the 
  skull is missing, scientists 
  don’t know if the small 
  nose crest was actually part 
  of a much longer crest like 
  that of Guanlong.
  u TARBOSAURUS was typical of the gigantic, late 
  tyrannosauroids, with a massive skull, powerful jaws, and  
  huge, banana-shaped teeth. In contrast, its arms were almost 
  ridiculously tiny and its hands had only two fingers each.
  Crest
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  182
  Tyrannosaurus
  Tyrannosaurus’s starring role in the movie 
  Jurassic Park conﬁrmed its status as the 
  most fearsome and famous dinosaur of 
  all. Though not the largest carnivore 
  ever to walk on land, it was the biggest 
  of its time, and the strength of its bite was 
  greater than that of any other land animal. 
  Some experts think Tyrannosaurus was a 
  scavenger as much as a killer, its huge jaws 
  and teeth adapted to eating bones.
  Tyrannosaurus
  TIE-ran-oh-SORE-us
   
  ■ When  70–65 million years ago (Late Cretaceous)
   
  ■ Fossil location  N. America
   
  ■ Habitat  Forests and swamps
   
  ■ Length  39 ft (12 m)
   
  ■ Diet  Flesh
  As long as a bus and twice the weight of an elephant, Tyrannosaurus 
  was undoubtedly the top predator in its environment. Deep holes in 
  the bones of prey such as Triceratops and Edmontosaurus show that 
  Tyrannosaurus used its immensely powerful jaws and bone-piercing 
  teeth as its main weapons. Small victims were probably shaken apart; 
  larger animals were crippled by horrible injuries. Holding the body 
  down with a foot, Tyrannosaurus used its huge neck muscles to tear oﬀ 
  mouthfuls of ﬂesh and bone with its mouth, before swallowing it all.
  . TINY ARMS Tyrannosaurus 
  had tiny arms and odd hands with 
  just two clawed ﬁngers each. The 
  arms could not reach the mouth or 
  even each other, but they were very 
  strong. Perhaps Tyrannosaurus dug 
  its claws into victims while holding 
  them in its mouth to stop them from 
  struggling free.
  u BONEMUNCHING TEETH
  Most carnivorous dinosaurs have 
  blade-like teeth with sawtooth edges,  
  but those of Tyrannosaurus were huge, 
  pointed spikes that could pierce skin, 
  muscle, and bone.
  u SKELETON About 30 Tyrannosaurus fossils 
  have been found, incuding several skeletons, though 
  none is complete. Skin impressions show adults had 
  scaly skin, but babies are likely to have had ﬂuﬀy 
  feathers like those of smaller tyrannosauroids.
  DINOSAURS AND BIRDS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  DINOSAURS AND BIRDS
  251 million years ago
  200
  145
  65
  Triassic
  Jurassic
  Cretaceous
  , LONG LEGS The hind legs were long, with 
  powerful thigh muscles but slender ankles and 
  feet. Their athletic build suggests Tyrannosaurus 
  could run very fast, though perhaps it did so only 
  rarely, since a high-speed fall could have proved 
  fatal for such a heavy animal.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  DINOSAURS AND BIRDS
  Compsognathids
  When most people think of a dinosaur they imagine something huge 
  and fierce like Tyrannosaurus, with its teeth bared, ready to kill. But 
  some members of the compsognathid family were no bigger than 
  chickens. The compsognathids were nimble little predators that 
  hunted small animals. They were 
  related to the ancestors  
  of birds and probably had 
  simple, fuzzy feathers  
  to keep their small 
  bodies warm.
  FAMILY FACT FILE
  Key features
   
  ■ Small, lightweight bodies with  
  hollow bones 
   
  ■ Skin covered with scales or furry feathers 
   
  ■ Long tails used for balance
  When
  Compsognathids first appeared in the  
  Late Jurassic, 151 million years ago.  
  They died out in the Early Cretaceous,  
  108 million years ago.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  DINOSAURS AND BIRDS
   
  ■ When  130–125 million years ago 
  (Early Cretaceous )
   
  ■ Fossil location  China 
   
  ■ Habitat  Woodlands 
   
  ■ Length  3 ft (1 m)
   
  ■ Diet  Small animals 
  In 1996 the first feathered dinosaur, 
  Sinosauropteryx, was discovered in the 
  Liaoning Quarry, China. The fossil 
  bore clear marks of simple, fluffy 
  feathers covering the back and sides of 
  the body. Such feathers probably served 
  to keep the animal warm by trapping a 
  layer of air next to the skin. 
  Sinosauropteryx
  SIGH-no-sore-OP-ter-ix
   
  ■ When  150 million years ago (Late Jurassic)
   
  ■ Fossil location  Germany, France
   
  ■ Habitat  Scrubland and marshes
   
  ■ Length  3 ft (1 m)
   
  ■ Diet  Lizards, small mammals, baby dinosaurs
  With its large eyes, clawed hands, and sharp, curved teeth, 
  Compsognathus was a typical carnivorous dinosaur, but it was 
  only the size of a chicken. Like a bird, it had hollow bones that 
  kept its body light. Running swiftly on the tips of its toes, this 
  lightweight predator could outpace fast-moving prey such as 
  lizards, before pouncing on its victim. Its long tail was more than 
  half of its total body length and was used for balance, helping it 
  make sharp turns as it dashed about. Scientists think fuzzy 
  feathers covered most of its body, especially its back.
  Compsognathus
  COMP-sog-NAITH-us
  Sinosauropteryx also had the longest 
  tail, relative to its body size, of any 
  flesh-eating dinosaur.
  d HUNTER OR SCAVENGER?
  Like any carnivore, Compsognathus sometimes came 
  across dead animals and would have scavenged for 
  scraps of meat. But its agile build and sharp little teeth 
  show it was more of a hunter than a scavenger, built to 
  capture nervous little animals before they scampered 
  under rocks or disappeared into the undergrowth.
  Compsognathus fossil
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  186
  DINOSAURS AND BIRDS
  Ornithomimids
  Also known as “ostrich dinosaurs,” the members of  
  the ornithomimid family were built like ostriches  
  and were just as quick on their feet. They were the  
  fastest dinosaurs of all, capable of reaching perhaps  
  50 mph (80 kph) when running. They evolved  
  from flesh-eaters, but their birdlike beaks and  
  lack of big teeth suggest a more varied diet.
   
  ■ When  75–65 million years ago (Late Cretaceous)
   
  ■ Fossil location  Mongolia
   
  ■ Habitat  Desert plains
   
  ■ Length  20 ft (6 m)
   
  ■ Diet  Leaves, seeds, insects, and small animals
  One of the best known of all ornithomimids  
  is Gallimimus (“chicken mimic”). It was the 
  largest ornithomimid, three times as tall as a 
  man and, at 1,000 lb (450 kg) in weight, a lot 
  , BIRD VISION 
  Gallimimus had 
  wide eye sockets 
  with eyes facing 
  sideways. This 
  helped it spot 
  enemies in almost any 
  direction. Inside each eyeball was a 
  supporting ring of small bony plates. 
  Modern birds still have this feature.
  Gallimimus
  GAL-ih-MIME-us
  heavier than any chicken. 
  Gallimimus was the fastest 
  sprinter of any dinosaur 
  and could have outrun a 
  racehorse. It had a birdlike skull, 
  with a brain about the size of a golf ball  
  (only slightly larger than an ostrich’s). Its  
  long, toothless beak was used to pick up  
  leaves, seeds, insects, and small mammals. 
  FAMILY FACT FILE
  Key features
   
  ■ Extremely long legs
   
  ■ Long necks and small, beaked heads
   
  ■ Large eyes
   
  ■ Tiny teeth or no teeth
   
  When
  Ornithomimids first appeared in the 
  Early Cretaceous, 130 million years ago. 
  They died out in the Late Cretaceous,  
  65 million years ago.
  Ornithomimids may have run just like 
  ostriches run today. Ostriches take great 
  strides with their powerful, long legs, with 
  their tails jutting out behind. The fastest bird 
  today, an ostrich can run at about 45 miles 
  (72 km) per hour, while an average human 
  can reach only 6–11 mph (10–18 kph). 
  LIVING RELATIVE
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  187
  DINOSAURS AND BIRDS
  Long, stiff tail
   
  ■ When  75 million years ago (Late Cretaceous)
   
  ■ Fossil location  Canada
   
  ■ Habitat  Open country, riverbanks
   
  ■ Length  15 ft (4 m)
   
  ■ Diet  Omnivorous
  Struthiomimus
  STROO-thee-oh-MIME-us
   
  ■ When  75–65 million years ago (Late Cretaceous)
   
  ■ Fossil location  USA, Canada
   
  ■ Habitat  Swamps, forests
   
  ■ Length  10 ft (3 m)
   
  ■ Diet  Omnivorous
  Ornithomimus had the typical short body 
  and long back legs of an ornithomimid. A fast 
  runner, it could make sudden turns even while 
  sprinting by swinging its tail from side to side. 
  For its size and time, it had a fairly large brain, 
  but was far less intelligent than an ostrich.
  Ornithomimus
  OR-nith-oh-MIME-us
  may also have included small animals  
  and insects. Like other ornithomimids, 
  Struthiomimus had long, powerful legs 
  built for speed, and a small head perched  
  on a slender, flexible neck.
  Struthiomimus was so similar to 
  Ornithomimus that its fossil was for 
  many years thought to be that of 
  Ornithomimus. The only difference is that 
  it had longer arms with stronger fingers.  
  At the ends of its fingers were long, 
  straight claws, but it probably could 
  not use them to grasp prey, like 
  Ornithomimus did. Instead, like modern 
  sloths, Struthiomimus may have used its 
  arms and hands to pull tree branches within 
  reach of its beak. It probably ate buds and 
  shoots from trees and other plants, but its diet 
  d FEATHERS OR SCALES? 
  Most models and artworks show ornithomimids with 
  scaly skin. However, many scientists now believe they 
  had primitive, fuzzy feathers (“protofeathers”), in 
  common with closely related dinosaur families.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  188
  Animatronic dinosaurs 
  You’ve probably seen dinosaurs brought to 
  life in movies, and you may have been lucky 
  enough to see a moving dinosaur at a 
  special exhibition. Some of these are 
  animatronic dinosaurs, and they take a long 
  time to build. They look very realistic, but 
  they are really just mechanical puppets.
  d LIFESIZED This animatronic 
  Tyrannosaurus was made for an 
  exhibition in 2007.
  Inner robot
  Animatronic dinosaurs are not completely 
  true-to-life. This Tyrannosaurus is much fatter than 
  it would have been, but a slender dinosaur body 
  would not have hidden the robot’s inner workings.
  DINOSAURS AND BIRDS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  189
  HOW IS IT DONE?
  An animatronic dinosaur begins life as a sketch, and 
  takes months to build. These pictures were taken 
  during the building of the Tyrannosaurus used in 
  The Lost World (1997), the second Jurassic Park ﬁlm. 
  Not all the dinosaurs in the Jurassic Park ﬁlms were 
  animatronic models. Many were “CG dinosaurs” 
  – computer-generated 3D models.
  u A BIG COVER UP The dinosaur’s skin is set over a plastic and steel 
  frame, much of which has to be welded into position.
  DINOSAURS AND BIRDS
  u KILLER JAWS Teeth are glued to the jaws, the mouth is lined with 
  ﬂesh-coloured latex, and ﬂexible skin is wrapped around the steel skull.
  u PUPPET MASTER The dinosaur’s movements are controlled by 
  a “telemetry suit” worn by an operator. This suit controls the arms.
  TAKE A LOOK
  Animatronic dinosaurs are not only used for ﬁlms 
  and shows. US scientist Peter Dilworth hopes  
  the technology will one day help people with 
  disabilities. His 45 cm (18 in) tall robotic 
  dinosaur is a replica of Troodon, a Cretaceous 
  meat-eating dinosaur. It was nicknamed 
  “Troody”. Troody took ﬁve years to develop and 
  can rise from a sitting position and walk on its own.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  DINOSAURS AND BIRDS
  Oviraptorosaurs
  The oviraptorosaurs are a family of odd-looking, 
  feathered dinosaurs with parrotlike beaks. Although 
  they evolved from ﬂesh-eating dinosaurs (theropods), 
  they were omnivores or plant-eaters. They had few or 
  no teeth, short snouts, and often a decorative crest on 
  the head. Fossils show they brooded their eggs as birds 
  do. Some oviraptorosaurs were so birdlike that the 
  scientists who discovered them thought  
  they must be ancient ﬂightless birds.
  Claws at tips  
  of long ﬁngers
   
  ■ When  75 million years ago (Late Cretaceous) 
   
  ■ Fossil location  Mongolia 
   
  ■ Habitat  Plains of Central Asia 
   
  ■ Length  9 ft (3 m)  
  FAMILY FACT FILE
  Citipati
  SIH-tee-PAH-tee
  Key features
   
  ■ Short skull, sometimes with a crest
   
  ■ Parrotlike beaks with small or no teeth
   
  ■ Feathers
   
  ■ Plant eaters
  When
  Oviraptorosaurs lived in  
  the Cretaceous Period, 
  between 84 and 65 
  million years ago.
  The most 
  distinctive 
  feature of 
  Citipati (below 
  and right) was the 
  crest on its head. 
  Many Citipati specimens have been found 
  crouching on their eggs in nests, sheltering 
  them with arms that were probably feathered, 
  as modern birds do. Citipati’s oval eggs were 
  huge—even bigger than a man’s hand.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  191
  DINOSAURS AND BIRDS
   
  ■ When  130–120 
  million years ago  
  (Early Cretaceous)
   
  ■ Fossil location 
  China 
   
  ■ Habitat  Lakesides 
  and riverbeds 
   
  ■ Length  3 ft (1 m) 
  Turkey-sized Caudipteryx was covered 
  in feathers. It had large plumes on 
  its short, winglike arms; a large 
  tail fan; and short, downy 
  feathers all over. The feathers were probably 
  used to keep it warm and to attract mates 
  rather than to fly. Caudipteryx’s bony tail was 
  shorter than that of most dinosaurs, which 
  meant it couldn’t be used as a counterbalance. 
  As a result, it most likely walked like a stocky, 
  flightless bird. Its pointed beak might have 
  been used to shred plants and crack seeds,  
  but Caudipteryx may also have eaten meat. 
  Caudipteryx
  caw-DIP-ter-ix
   
  ■ When  70 million years ago (Late 
  Cretaceous) 
   
  ■ Fossil location  Mongolia
   
  ■ Habitat  Woodlands
   
  ■ Length  5 ft (1.5 m)  
  Ingenia was a small, feathered 
  dinosaur, barely as tall as a 
  man. It was named after the 
  Ingen province in Mongolia 
  where it was first found.  
  Very few fossils of this 
  dinosaur have been 
  discovered. From the 
  existing specimens, however, scientists  
  know it had stout hands with unusually  
  large thumbs and thumb claws, which may 
  Ingenia
  IN-jeh-NEE-ah
  have been defensive weapons. Ingenia may 
  have been an omnivore, feeding on a mix  
  of plant and animal food.
  Fan of 
  feathers  
  on tail
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  DINOSAURS AND BIRDS
  DINOSAUR EGGS
  In the 1920s, scientists found this amazing 75-million-year-old 
  nest buried deep in the sands of the Gobi Desert in Mongolia. 
  In it were a number of long, narrow eggs arranged in a circle. 
  This was the fossilized nest of an Oviraptor, a type of feathered 
  dinosaur. The scientists also found the skeleton of the mother 
  near to the nest, but at first they mistook mother and eggs for 
  two different species. They named the mother Oviraptor, 
  meaning “egg thief,” thinking she was a predator trying to steal 
  the eggs. The name stuck, and all dinosaurs in the same family 
  are now called oviraptorosaurs.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  DINOSAURS AND BIRDS
  u INSIDE THE EGG Scientists have found many clutches 
  of dinosaur eggs, but not all of them contain baby dinosaurs. 
  To find out if anything is inside, the eggs are scanned and the 
  rock is then carefully chipped with tiny chisels or dissolved in 
  weak acid. It can take as long as a year to reveal the tiny bones 
  and tissues of an embryo hidden inside the egg.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  194
  DINOSAURS AND BIRDS
  194
  Therizinosaurs
  When scientists put together bits and pieces of 
  therizinosaur fossils, they turned out to be some  
  of the most bizarre-looking dinosaurs ever. They  
  were tall with small heads, stumpy feet, and pot 
  bellies. While their bones show they were relatives of 
  predatory dinosaurs, their teeth and digestive system 
  seem to have evolved to eat plants instead of meat. 
  u SCISSOR HANDS 
  Therizinosaurus had astonishingly 
  long claws on its hands, each measuring 
  nearly 3 ft (1 m) long. These may  
  have been defensive weapons used for 
  slashing at tyrannosaurids, such as the 
  Tarbosaurus shown here. They might 
  also have been used to pull high 
  branches down from trees.
   
  ■ When  80–70 million years ago (Late Cretaceous)
   
  ■ Fossil location  Mongolia
   
  ■ Habitat  Woodlands
   
  ■ Length  26–36 ft (8–11 m)
   
  ■ Diet  Plants
  Therizinosaurus was one of the bigger 
  therizinosaurs. Its fossils were found in  
  what is now the cold, barren Gobi Desert. 
  During the Late Cretaceous, this region 
  was warmer and wetter, with tall trees. 
  Perhaps Therizinosaurus’s immense 
  height helped it to gather leaves 
  from tall trees, like a giraﬀe.
  Therizinosaurus
  THERRY-zin-oh-SORE-us
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  195
  DINOSAURS AND BIRDS
   
  ■ When  130 million years ago (Early Cretaceous)
   
  ■ Fossil location  China
   
  ■ Habitat  Woodlands
   
  ■ Length  13 ft (4 m) 
   
  ■ Diet  Plants
  In 1988, five specimens of a 
  previously unknown dinosaur 
  were found in Mongolia. This was 
  Alxasaurus, a therizinosaur. Its 
  leaf-shaped teeth were not sharp 
  enough to tear off flesh, so it 
  probably fed on plants. The swollen 
  stomach of Alxasaurus indicates that 
  it ate great quantities of leaves. Its big 
  belly may have made it too clumsy  
  to run fast. If attacked by another 
  dinosaur, it probably lashed out 
  with its claws rather than 
  trying to escape.
  FAMILY FACT FILE
  Key features
   
  ■ Long necks
   
  ■ Enormous curved claws on fingers
   
  ■ Short tails
   
  ■ Four-toed feet
   
  ■ Partly feathered
  When
  Therizinosaurs first appeared in 
  the Early Cretaceous, 130 million 
  years ago. They died out in the Late 
  Cretaceous, 65 million years ago.
  Model based on a fossilized therizinosaur 
  embryo found inside an egg.
  Alxasaurus
  ALK-sah-SORE-us
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  196
  DINOSAURS AND BIRDS
  Dromaeosaurs
  The dromaeosaurs were small but ferocious hunters 
  with bladelike teeth and vicious, hooked claws on their 
  hands and feet. They were closely related to birds and 
  may have evolved from a flying ancestor. Their long 
  arms folded up like wings, and their bodies were 
  fully feathered. Dromaeosaurs are sometimes 
  also called “raptors,” a word that means 
  “thief” or “grabber.” 
   
  ■ When  130–120 million years ago (Early Cretaceous)
   
  ■ Fossil location  USA
   
  ■ Habitat  Plains
   
  ■ Length  23 ft (7 m)
   
  ■ Diet  Flesh
  Utahraptor was the largest dromaeosaur 
  and reached about half a ton in weight,  
  making it heavier than a grizzly bear. Like  
  other dromaeosaurs, it had a large, hooked  
  claw on its second toe that it might have  
  used for slashing or stabbing a victim after  
  leaping on it. One fossilized claw measures  
  9 in (24 cm) in length.
  Utahraptor 
  YOU-tah-RAP-tor
  Dromaeosaurus
  DROM-ee-oh-SORE-us
   
  ■ When  75 million years ago (Late Cretaceous)
   
  ■ Fossil location  Canada
   
  ■ Habitat  Forests, plains
   
  ■ Length  6½ ft (2 m)
   
  ■ Diet  Flesh
  About the size of Velociraptor, Dromaeosaurus 
  had a stockier skull and a deeper lower jaw, 
  suggesting it had a more powerful bite. It  
  had large eyes and hunted by vision, perhaps 
  stalking prey quietly like a cat does before 
  leaping for the kill. Only a partial skull 
  and a few bones of Dromaeosaurus 
  have been found. The skeleton 
  shown below is based on 
  these and other closely 
  related dromaeosaurs. 
  Three clawed 
  fingers on each 
  hand
  Slender, 
  flexible 
  neck
  Toe claw
  Dromaeosaurus 
  reconstruction
  Long arms
  Toe claw
  Dromaeosaurus 
  skull
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  197
  DINOSAURS AND BIRDS
   
  ■ When  85 million years ago (Late Cretaceous)
   
  ■ Fossil location  Mongolia
   
  ■ Habitat  Scrubland and deserts
   
  ■ Length  6½ ft (2 m)
   
  ■ Diet  Lizards, mammals, small dinosaurs
  Velociraptor played a starring role in Jurassic 
  Park, where it was shown as twice its actual size. 
  In reality it was a slender, feathered animal 
  about the size of a wolf. The most spectacular 
  fossil of Velociraptor is a complete 
  skeleton locked in combat 
  with a Protoceratops (below). 
  Velociraptor
  vel-OSS-ee-rap-tor
  They died in midfight, perhaps buried by a 
  sudden sandstorm. Like other dromaeosaurs, 
  Velociraptor had huge, flickable toe claws and 
  long, clawed arms that unfolded like wings to 
  grapple prey. Although no feathered fossils of 
  Velociraptor have been found, its arm bones 
  have “quill nodes”—small 
  bumps to which long 
  feathers were anchored. 
  Deinonychus
  dye-NON-ee-cuss
   
  ■ When  75 million years ago (Late Cretaceous)
   
  ■ Fossil location  N. America
   
  ■ Habitat  Woodland
   
  ■ Length  2 ft (6 m)
   
  ■ Diet  Flesh
  In 1995, 14-year-old Wes Linster was hunting 
  for fossils with his parents in the mountains of 
  Glacier National Park in Montana. He was 
  thrilled to find parts of a skeleton. Later 
  excavation revealed that Wes had found a tiny 
  but perfectly preserved dromaeosaur. Because 
  Bambiraptor
  BAM-bee-rap-tor
  of its size, scientists named it after the Disney 
  character Bambi the deer. Bambiraptor was 
  birdlike and probably feathered, with long 
  hindlimbs that suggest it was a fast runner.  
  It probably hunted small mammals and 
  reptiles, snatching them in its clawed hands  
  as a cat catches a mouse. It had a very large 
  brain relative to its body size, suggesting it  
  was a quick-witted animal (or an infant).  
  Some scientists think its small size allowed  
  it to climb trees.
   
  ■ When  115–108 million 
  years ago (Early Cretaceous)
   
  ■ Fossil location  USA
   
  ■ Habitat  Subtropical swamps and forests
   
  ■ Length  10 ft (3 m)
   
  ■ Diet  Flesh
  Leopard-sized Deinonychus (“terrible claw”) 
  is famous for its large toe claws. As in other 
  dromaeosaurs, the claws flipped up off the 
  ground when it was walking in order to stay 
  sharp. Some experts think Deinonychus used 
  its toe claws to slash the throat or belly of prey 
  while kicking violently. Others think the claws 
  were climbing aids in juveniles or used for 
  clinging to prey. A stiff tail provided balance 
  when leaping or climbing.
  Toe claw
  Unusually  
  slender snout
  Long sharp claw
  Stiffened tail  
  hinged at base
  Birdlike wrist joint allowed 
  Bambiraptor to fold its hands 
  as a bird folds its wings.
  FAMILY FACT FILE
  Key features
   
  ■ Long, birdlike feathers on the arms, 
  legs, and tail; downy feathers on body
   
  ■ Sickle-shaped claw on second toe
   
  ■ Long arms that fold against the body 
  like wings
  When
  Dromaeosaurs appeared in the Jurassic, 
  167 million years ago, and died out at 
  the end of the Cretaceous, 65 million 
  years ago.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  198
  Fight to the death
  In North America, teeth of the ferocious 
  dinosaur Deinonychus are often found 
  near remains of the huge plant-eater 
  Tenontosaurus. At one site, a group 
  of ﬁve Deinonychus was found 
  with a Tenontosaurus. The plant-
  eater was much too big for  
  a Deinonychus to kill on its 
  own, but could they have 
  been hunting as a pack?
  DINOSAURS AND BIRDS
  PACK HUNTING
  Pack hunters such as wolves can bring down 
  huge prey by cooperating. There’s no proof 
  dinosaurs hunted in packs, and not all scientists 
  think they did. In birds—the living descendants 
  of dinosaurs—pack hunting is almost unknown.
  , SOFT TARGET? 
  Tenontosaurus had no 
  protective armor and few 
  weapons, making it a soft 
  target for predators. But  
  its great size helped defend 
  it. At about 2 tons in 
  weight, an adult was  
  nearly 30 times heavier  
  than Deinonychus.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  199
  DINOSAURS AND BIRDS
  , DEINONYCHUS’S JAWS 
  contained about 60 curved, bladelike 
  teeth, each with a sawtooth edge like 
  the blade of a steak knife. Such teeth 
  were ideal for slicing through tough 
  skin and ﬂesh.
  DID YOU KNOW?
  Deinonychus’s most famous feature, an enlarged 
  claw on the second toe of its hind feet, provided 
  its name, which means “terrible claw.” 
  u THE SECOND CLAW might have 
  been used to disembowel prey, with the 
  predator slicing open the prey’s stomach 
  area with a series of raking kicks.
  , A LIGHTWEIGHT 
  hunter such as Deinonychus 
  would have been amazingly 
  agile—a quality it would have 
  needed to dodge the swinging 
  tail and ﬂailing limbs of heavy 
  prey such as Tenontosaurus.
  Curved 
  sickle 
  claw
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  200
  DINOSAURS AND BIRDS
  Microraptor
  Only slightly larger than a pigeon, 
  Microraptor (“tiny thief”) is one 
  of the smallest known dinosaurs. 
  It was completely covered with 
  feathers and could fly (or at least 
  glide) from tree to tree, sailing  
  on what appear to be four wings.  
  A member of the dromaeosaur 
  family, Microraptor was a 
  carnivore and a close relative 
  of Velociraptor, but it wasn’t 
  a true bird.
   
  ■ When  130–125 million years ago (Early Cretaceous)
   
  ■ Fossil location  China
   
  ■ Habitat  Woodlands
   
  ■ Length  3 ft (1 m)
   
  ■ Diet  Probably small mammals, lizards, and insects
  Scientists have found dozens of fossils of 
  Microraptor in China, including more than 
  20 well-preserved skeletons. Unlike a bird,  
  this creature had teeth, a bony tail, and front 
  legs with large claws, but its fossils also show 
  unmistakeable signs of flight feathers, proving 
  that feathers are not a unique feature of  
  birds but were found in other dinosaurs too. 
  Microraptor didn’t have the big flight muscles 
  needed to take off by flapping, but it could 
  have used its wings for gliding, much like a 
  flying squirrel. Its tail had a diamond-shaped 
  fan of feathers at the end, perhaps to steady it in 
  midair. The long feathers on its feet would have 
  gotten in the way when walking or running, so 
  perhaps Microraptor stayed in the trees.
  Microraptor
  MY-crow-rap-tor
  251 million years ago
  200
  145
  65
  Triassic
  Jurassic
  Cretaceous
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  201
  DINOSAURS AND BIRDS
  A FOUR-WINGED 
  DINOSAUR?
  Microraptor had long, bird-style 
  flight feathers on its arms and 
  legs, giving it what seem to be 
  four wings. How it used these  
  is a mystery. Some scientists 
  suggest it could spread out its 
  hind legs when gliding, but  
  its hip joints may not have had 
  enough flexibility to do this.
  , FEATHERED FOSSIL 
  This well-preserved fossil shows 
  impressions of long feathers on the 
  arms and legs. A stiff tail, typical  
  of a dromaeosaur, is also visible.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  202
  DINOSAURS AND BIRDS
  Sinornithosaurus
  Sinornithosaurus was an early member of the 
  dromaeosaur family. As this beautiful fossil  
  shows, its entire body was covered from head 
  to tail with feathers. Sinornithosaurus 
  means “Chinese bird lizard,” but this 
  species wasn’t a true bird, since it was 
  probably too heavy to fly, although like 
  other dromaeosaurs it may have 
  evolved from a flying ancestor.
   
  ■ When  130–125 million years ago (Early Cretaceous)
   
  ■ Fossil location  China
   
  ■ Habitat  Woodlands
   
  ■ Length  3 ft (1 m)
   
  ■ Diet  Probably omnivorous
  Several well-preserved fossils of Sinornithosaurus have 
  been found in China since 1999, including the amazingly 
  complete fossil shown here (nicknamed “Dave”), which  
  shows the precise distribution of feathers on the body. 
  Sinornithosaurus was a ground-dwelling predator that hunted 
  small animals, including other dinosaurs. Although it  
  couldn’t fly, some scientists think it could climb trees.
  Sinornithosaurus
  sine-OR-nith-oh-SORE-us
  Venomous or not?
  In 2009, scientists noticed something strange 
  about Sinornithosaurus: it had unusually long, 
  fanglike teeth with prominent grooves, similar 
  to those of venomous snakes and lizards today. 
  They suggested that Sinornithosaurus was 
  venomous (able to inject poison into prey with 
  a bite or a sting). Other scientists disagree with 
  this theory, saying that these grooves could 
  simply be normal wear and tear, and that other 
  dinosaurs had grooved teeth, too.
  Fossil fish
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  203
  DINOSAURS AND BIRDS
  u FUZZY FEATHERS Sinornithosaurus 
  probably had feathers in various colors and sizes. 
  Fluffy ones on its body may have helped in trapping 
  heat. Long feathers on its arms were perhaps used  
  for show or for protecting its young.
  251 million years ago
  200
  145
  65
  Triassic
  Jurassic
  Cretaceous
  Claw
  Feathers  
  on head
  Feathers
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  204
  Troodon
  Troodon was a small but agile dinosaur, 
  built like a bird and covered with feathers. 
  About the weight of a child, it wasn’t 
  powerful enough to tackle large 
  dinosaurs, but it was swift on its feet 
  and adept at catching small animals in 
  the undergrowth of woodlands. With an 
  unusually large brain for a dinosaur and 
  sharp eyes, Troodon seems to have been a 
  quick-witted hunter with the lightning 
  reactions and killer instinct of a cat.
  Seen by left eye
  Seen by both eyes, 
  giving 3-D vision
  Seen by 
  right eye
   
  ■ When  74–65 million years ago 
  (Late Cretaceous) 
   
  ■ Fossil location  N. America 
   
  ■ Habitat  Wooded plains 
   
  ■ Length  10 ft (3 m) 
   
  ■ Diet  Small animals and possibly plants
  Troodon had unusual teeth with very 
  jagged edges. Although small animals 
  probably made up most of its diet,  
  the teeth might also have been used for 
  shredding leaves. The name Troodon 
  means “wounding tooth.”
  ON THE CHASE 
  Long, slender legs and an athletic build made Troodon a 
  fast sprinter, able to outrun small animals such as lizards 
  and baby dinosaurs. The second toe on each foot had a 
  large, sickle-shaped claw that Troodon may have used to 
  pin down prey. The claw could swivel upward to stay 
  off the ground while Troodon was running. 
  DINOSAURS AND BIRDS
  . 3-D VISION
  Troodon’s eyes, 
  unlike those of most  
  dinosaurs, faced forward rather 
  than sideways. This gave it 3-D  
  vision in the area seen by both  
  eyes (as in humans).This special 
  ability enabled Troodon to judge 
  the distance to its prey before 
  pouncing for the kill.
  Troodon
  TROH-o-don
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  205
  The legs were 
  tightly folded 
  inside the egg.
  DINOSAURS AND BIRDS
  u TROODON EGGS were found at Egg Mountain in 
  Montana. Scientists used the tiny bones in a fossil egg to recreate 
  this lifelike model of a baby Troodon about to hatch. Both parents 
  sat in egg-filled nests, using their feathered arms to protect the eggs.
  251 million years ago
  200
  145
  65
  Triassic
  Jurassic
  Cretaceous
  Troodon had perhaps the largest brain relative 
  to its body weight of any dinosaur. But while  
  it may have been a quick thinker by dinosaur 
  standards, its 
  brain was only 
  as big as that of 
  a ﬂightless bird 
  such as a cassowary 
  and much smaller  
  than the average 
  mammal’s brain.
  BIRDBRAINED
  Cassowary
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  206
  DINOSAURS AND BIRDS
  Death of the dinosaurs
  Just before the dinosaurs ﬁrst emerged, Earth suﬀered 
  a mass extinction that wiped out nearly 90 percent  
  of all species. The planet took millions of years to 
  recover. Then, 65 million years ago, virtually all 
  dinosaurs were wiped out in another sudden mass 
  death. What caused their mysterious disappearance?
  ATTACK FROM ABOVE
  In 1980, an American scientist named 
  Luis Alvarez made an amazing discovery. 
  Studying rocks that formed at around the 
  time the dinosaurs disappeared, he found 
  that the level of iridium (a metal that’s 
  rare on Earth but common in meteorites) 
  was 100 times higher than normal.  
  He found the same high level all over  
  the world and concluded that a massive 
  meteorite or asteroid must have slammed 
  into Earth. Such a huge impact could 
  have wrecked Earth’s climate and killed 
  oﬀ the dinosaurs.
  Coal
  Iridium layer
  Clay
  DID YOU KNOW?
  Not all animals perished. Those that survived 
  included:
   
  ■ Sharks and other ﬁsh
   
  ■ Jellyﬁsh
   
  ■ Scorpions
   
  ■ Birds
   
  ■ Insects
   
  ■ Mammals
   
  ■ Snakes
   
  ■ Turtles
   
  ■ Crocodiles
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  207
  DINOSAURS AND BIRDS
  What did the meteorite do?
  A huge meteorite smashing into Earth 
  would have created a worldwide cloud 
  of dust and fumes, choking animals  
  and blocking out the Sun’s light and 
  warmth. The planet’s climate would 
  have changed dramatically,  
  making life impossible  
  for many species.
  Hidden crater
  A meteorite produces a crater, and a meteorite 
  big enough to change the world’s climate 
  would produce a giant crater,  
  so where is it? The answer came 
  in the 1970s when scientists 
  searching for oil found a vast 
  crater buried more than half 
  a mile (1 km) underground 
  on the coast of Mexico. The 
  space rock that left this scar 
  was an estimated 6 miles 
  (10 km) wide and would 
  have hit the Earth with 
  tremendous force, sending 
  shockwaves all over the world.
  Double trouble
  The meteorite impact almost certainly 
  contributed to the death of the dinosaurs, 
  but other catastrophic events were going 
  on at the same time, and some scientists 
  believe that it was a chain of events rather 
  than simply one meteorite that caused the 
  mass extinction. Heavy volcanic activity 
  in western India was sending up huge 
  clouds of gas that would have contributed 
  to climate changes.
  No land animal larger 
  than a dog survived 
  the mass extinction 
  that killed the 
  dinosaurs.
  FACT FILE
  There are been five major extinctions  
  in the past 550 million years. A mass 
  extinction means that more than  
  50 percent of animal species die at one 
  time. The mass extinction that ended the 
  Mesozoic Era (the time of the dinosaurs) 
  was the most recent, and more than  
  80 theories have been put forward to 
  account for what happened.
  The Chicxulub crater was about 
  112 miles (180 km) wide.
  The sea would have ﬁlled the 
  Chicxulub crater with water 
  soon after the impact.
  Volcanic activity created the Deccan Traps lava beds, 
  which at one point covered more than half of India.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  208
  DINOSAURS AND BIRDS
  Early birds
  Birds evolved from dromaeosaur-like dinosaurs during 
  the Jurassic Period. The ﬁrst birds had skeletons like 
  those of Microraptor (page 198). Over time, as birds 
  adapted to life in the air, they evolved huge ﬂight muscles 
  and lost their teeth, tails, and 
  claws, making them 
  more lightweight.
  Very long feathered  
  arms with ﬂight feathers
  Modern birds have a toothless 
  beak, but Archaeopteryx had 
  jaws and teeth typical of a 
  carnivorous dinosaur.
   
  ■ When  130–120 million years ago (Early Cretaceous) 
   
  ■ Fossil location  China 
   
  ■ Habitat  Woodlands of Asia 
   
  ■ Length  1 ft (0.3 m)
   
  ■ Diet  Probably seeds  
  Confuciusornis was the earliest toothless bird 
  and the ﬁrst known to have a beak. It also had  
  a stumpy tail like that of modern birds, but it 
  lacked strong ﬂight muscles. Thousands of 
  fossils of Confuciusornis 
  have been found in 
  China, and some of 
  the adults have 
  very long tail 
  feathers. These 
  may be male 
  ornaments that 
  were displayed  
  to attract females 
  during 
  courtship.
   
  ■ When  150 million years ago (Late Jurassic) 
   
  ■ Fossil location  Germany 
   
  ■ Habitat  Forests and lakes of western Europe 
   
  ■ Length  1 ft (0.3 m)
   
  ■ Diet  Insects, probably reptiles  
  When the ﬁrst complete fossil of Archaeopteryx 
  was discovered in 1861, scientists were 
  amazed—it looked like a cross between a 
  , THIS FOSSIL of Archaeopteryx was 
  discovered in Germany. Amazingly clear 
  impressions of feathers on the arms and tail  
  are preserved in ﬁne-grained limestone.
  FAMILY FACT FILE
  Confuciusornis
  con-FEW-shus-OR-niss
  Archaeopteryx
  ar-kee-OP-ter-ix
  Key features of modern birds
   
  ■ Feathered body and wings
   
  ■ Toothless beaks
   
  ■ Tail bones fused into a stump
   
  ■ No finger claws or small finger claws
   
  ■ Deep keel bone on breast to anchor 
  large flight muscles
   
  ■ Semicircular wrist bone to aid flapping
  When
  Birds first appeared in the Late Jurassic 
  and have been in the skies ever since.
  dinosaur and a 
  bird. It had a fully 
  feathered tail and wings, yet it also had 
  dromaeosaur-like claws on its hands,  
  bones along its tail, and jaws with teeth  
  instead of a beak. Archaeopteryx is the oldest 
  known member of the bird family. It was the 
  size a pigeon and had long ﬂight feathers, but  
  it lacked the powerful muscles needed for 
  ﬂapping ﬂight and was probably more of  
  a glider than a ﬂapper.
  Archaeopteryx
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  209
  DINOSAURS AND BIRDS
  Toothed beak
  Backward-pointing toe for perching
  Clawed fingers
  Long beak filled 
  with sharp teeth
  Large head
  Long, slender 
  body
   
  ■ When  90–75 million years ago (Late Cretaceous) 
   
  ■ Fossil location  USA 
   
  ■ Habitat  Seashores 
   
  ■ Length  2 ft (0.6 m)  
   
  ■ Diet  Fish  
   
  ■ When  75 million years ago (Late Cretaceous) 
   
  ■ Fossil location  USA 
   
  ■ Habitat  Coastal waters 
   
  ■ Length  6 ft (1.8 m) 
   
  ■ Diet  Fish and squid 
   
  ■ When  65 million years ago (Late Cretaceous) 
   
  ■ Fossil location  Antarctica 
   
  ■ Habitat  Coast of Antarctica 
   
  ■ Length  2 ft (0.6 m) 
   
  ■ Diet  Water plants  
  Fossils of Vegavis, a relative 
  of ducks and geese, were 
  found in Antarctica in 1992. 
  The discovery was important 
  because it showed that some  
  of today’s bird families had  
  already evolved during the age  
  of dinosaurs. Vegavis lived in 
  Antarctica when its climate  
  was much less cold than today.
   
  ■ When  135–120 million years ago (Early Cretaceous) 
   
  ■ Fossil location  Spain 
   
  ■ Habitat  Woodlands of western Europe 
   
  ■ Length  8 in (20 cm)
   
  ■ Diet  Probably insects  
  Iberomesornis was about the size of a finch. It 
  had a stumpy tail and powerful chest muscles, 
  indicating it was a good flyer, and its curved 
  foot claws suggest it perched on 
  trees. But it had features similar 
  to a dinosaur, too, including 
  large claws on its wings.
  Ichthyornis
  ICK-thee-OR-niss
  Hesperornis
  hess-per-ORE-niss
  Vegavis
  VAY-gah-viss
  Iberomesornis
  I-beh-ro-may-SORE-niss
  Hesperornis was an enormous 
  seabird that had lost the power of flight but 
  become an expert diver. It used its huge feet  
  to push itself through the water as it chased 
  squid and fish, which it caught in a toothed 
  beak. The bones of its hands and forearms  
  had vanished, leaving tiny “wings” that it 
  likely used for steering in water. Like all  
  birds, Hesperornis nested on land, but it 
  was probably unable to walk and had to  
  push itself along on its belly.
  Ichthyornis (“fish bird”) was a 
  seabird, similar in size and weight 
  to a modern seagull, but its head 
  and beak were much larger. It had 
  a large, keeled breastbone, showing 
  it had powerful breast muscles and 
  was a strong flyer. However, its 
  jaws were packed with small, curved 
  teeth just like those of 
  prehistoric fish-eating lizards 
  called mosasaurs. It may even 
  have fed like one, using its  
  long snout and hooked teeth to 
  snatch fish and other slippery prey 
  from the water. Ichthyornis also had 
  webbed feet with short claws.
  Tiny wings
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  DINOSAURS AND BIRDS
  Late birds
  Although most dinosaurs disappeared 65 million years ago, 
  birds continued to flourish. During the Cenozoic—the era  
  that followed the age of the dinosaurs—birds evolved into a  
  vast range of new species. Some became masters of the sky or 
  took to the water. Others gave up flying and evolved into huge 
  carnivores, filling the gap that the dinosaurs had left open.
   
  ■ When  5–2 million years ago (Neogene)
   
  ■ Fossil location  North and South America
   
  ■ Habitat  Grassy plains
   
  ■ Height  8 ft (2 m)
   
  ■ Diet  Meat
  Also known as a “terror bird,” Titanis was a 
  gigantic, flightless carnivore as fearsome as a 
  dinosaur. It was twice the weight of a man 
  but much faster, capable of running at up to 
  perhaps 40 mph (65 kph). It used a huge, 
  hooked beak to kill prey and rip open their 
  bodies. Titanis lived at the same time as 
  prehistoric humans were beginning to walk 
  on land and spread, but the two never met as 
  Titanis lived only in the Americas. Among its 
  prey was the prehistoric horse Hipparion.
  Titanis 
  tie-TAN-iss
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  DINOSAURS AND BIRDS
  Ducklike beak
  Enormous wings
   
  ■ When  62–55 million years ago (Paleogene)
   
  ■ Fossil location  N. America, S. America, Europe
   
  ■ Habitat  Lake shores
   
  ■ Height  3 ft (1 m)
   
  ■ Diet  Plankton, water plants
  Presbyornis looked like a tall duck. Large 
  numbers of fossils, as well as eggs and 
  nests, have been found in sites in North 
  America that were once shallow lakes. 
  Perhaps Presbyornis lived in huge ﬂocks by 
  the shore, the birds wading into the shallows  
  to feed, using their beaks to ﬁlter food from  
  the water, as ducks do. Presbyornis was one 
  of the most successful birds of its time,  
  living for millions of years.
   
  ■ When  6 million years ago (Neogene)
   
  ■ Fossil location  Argentina
   
  ■ Habitat  Inland and mountainous areas
   
  ■ Wingspan  26 ft (8 m)
   
  ■ Diet  Meat
   
  ■ When  2 million–200 years ago
  (Neogene)
   
  ■ Fossil location  New Zealand
   
  ■ Habitat  Plains
   
  ■ Height  12 ft (4 m)
   
  ■ Diet  Plants
  Twice the height of a man, 
  Dinornis (also called the giant 
  moa) was the tallest ﬂightless bird that ever 
  lived. Flocks of Dinornis lived in New Zealand 
  until humans settled on the islands about  
  700 years ago and hunted them to extinction. 
  Dinornis belonged to the same bird family 
  (ratites) as the emu, ostrich, and kiwi.
  Presbyornis
  PREZ-bee-OR-niss
  Argentavis
  AR-jen-TAY-viss
  Dinornis
  die-NOR-niss
  Argentavis was the largest 
  bird that ever ﬂew, with a 
  wingspan more than twice that of 
  today’s record holder, the wandering 
  albatross. As heavy as a man, it used 
  its vast wings to catch rising air currents and so keep its body 
  aloft, gliding eﬀortlessly as it scanned the landscape for food. 
  Some experts think Argentavis was a hunter that could swoop 
  down and snatch prey. Others think it scavenged like a vulture.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  DINOSAURS AND BIRDS
  Gastornis
  Fifty million years ago, when Europe and North America 
  were covered with lush tropical forests, a giant flightless 
  bird prowled through the undergrowth. Gastornis was 
  taller than a man and had a head as large as a horse’s. Its 
  beak was gigantic and its bite immensely powerful—but 
  whether it used it to tear flesh, crack bones, or merely 
  munch on leaves remains an unsolved mystery.
  Footprint on sandstone
  In 2009, a 50-million-year-old 
  footprint made by Gastornis was 
  found in a slab of rock in Washington 
  State. To protect the find from rainy 
  weather and fossil thieves, the slab  
  was airlifted in a helicopter to Western 
  Washington University, where it now 
  lies safely.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  DINOSAURS AND BIRDS
   
  ■ When  55–45 million years ago (Paleogene) 
   
  ■ Fossil location  Europe and N. America 
   
  ■ Habitat  Tropical and subtropical forests 
   
  ■ Length  Over 6½ ft (2 m) 
   
  ■ Diet  Unknown 
  Discovered in France in 1855, Gastornis was named after 
  Gaston Plante, the scientist who found it. A similar bird 
  called Diatryma was later found in North America and is 
  now thought to be the same creature. Gastornis had large, 
  powerful legs but didn’t have the athletic build of a fast 
  runner. Perhaps it was an ambush hunter, hiding in dense 
  forest and waiting for small animals to wander close, before 
  stamping them to death with its giant feet or snatching 
  them in its beak. Some experts think it was a plant-eater 
  and used its beak to crush tough leaves. Others  
  think it was a scavenger that fed on corpses.
  Gastornis
  gas-TORE-niss
  u MONSTROUS BEAK 
  Gastornis’s huge beak had a slightly 
  hooked tip, like that of a bird of prey. 
  According to some scientists, its bite 
  was strong enough to crack open 
  coconuts and bones. Males and females 
  had similar beaks, so the large size 
  probably didn’t evolve for attraction.
  Name game
  For more than 100 years, scientists 
  thought Diatryma from America and 
  Gastornis from Europe were totally 
  different. But then someone realized 
  that the Gastornis fossils had been put 
  together incorrectly and they were 
  actually the same bird. Now both are 
  known as Gastornis, the older name.
  Tiny, useless 
  wing
  251 million years ago
  200
  145
  65
  Triassic
  Jurassic
  Cretaceous
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  214
  MAMMALS
  MAMMALS
  u SINOCONODON This mammal 
  roamed Early Jurassic China. It was just  
  12 inches (30 cm) in length and is one of 
  the earliest known mammals. It probably 
  preyed on insects and small reptiles.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  215
  After the dinosaurs 
  perished, mammals took 
  over and became the 
  dominant animals on land. 
  Mammals are hairy, 
  warm-blooded animals 
  that feed their young on 
  milk (such as humans). 
  MAMMALS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  216
  What are mammals?
  When the dinosaurs were wiped out, it gave a group of small, warm-blooded 
  animals the chance they needed to thrive. These were the mammals, distinct 
  from other animals largely because they feed their young on milk.
  There are now around 5,000 species of mammal.  
  They are grouped into diﬀerent families and orders, including: 
  Marsupials are a group of mammals 
  found in Australasia and the Americas. 
  They give birth to tiny, undeveloped 
  young. Many marsupials 
  have a pouch. The 
  newborn crawls 
  into the pouch  
  to feed on milk  
  and complete its 
  development.
  MARSUPIALS
  BATS
  RODENTS
  . GRAY 
  KANGAROO 
  A kangaroo’s pouch 
  faces up but other 
  marsupials have 
  pouches that face down. 
  Young kangaroos are 
  called joeys.
  . BIGGEST The 
  Malaysian ﬂying fox is 
  the largest bat, with a 
  wingspan that can reach 
  5 ft (1.5 m).
  There are more species of rodent than 
  any other mammal. Most rodents are 
  small and many, such as mice, have a 
  long tail. They all have clawed feet, 
  long whiskers, and large gnawing teeth 
  (incisors) at the front of their mouths. 
  Bats are the only mammals that can  
  ﬂy (rather than glide). They include  
  the world’s smallest mammal, Kitti’s 
  hog-nosed bat. Their wings are formed 
  from a double layer of skin.
  .  KOALA A baby 
  koala will spend more 
  than six months in its 
  mother’s pouch.
  MAMMALS
  . GRAY 
  LONGEARED BAT 
  Long ears help this  
  bat pick up sounds, 
  leading it to its  
  prey—a moth in  
  this case.
  d PRAIRIE DOGS live in burrows that 
  join those of neighbors, forming “towns.” 
  . CAPYBARA This 
  is the world’s largest 
  rodent, reaching 
  lengths of up to  
  4 ft (1.3 m).
  , SMALLEST 
  Kitti’s hog-nosed 
  bat is just 11⁄4 in 
  (3 cm) long.
  u DORIA’S TREE 
  KANGAROO  
  These unusual climbing 
  kangaroos live in trees.
  Cape porcupine 
  (well protected 
  by its spines, 
  or quills).
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  217
  CETACEANS
  CARNIVORES
  HOOFED MAMMALS
  Although whales 
  and dolphins 
  spend their lives in 
  water, they have to 
  come to the surface 
  to breath air; they 
  have lungs, just like 
  other mammals.
  u BOTTLENOSE 
  DOLPHIN Dolphins 
  are a type of toothed whale. 
  They live in groups.
  Most hoofed mammals walk and 
  run on the tips of their toes on 
  hooves, which are simply large, 
  heavy-duty toenails. This is a 
  large and varied group, and 
  all are herbivores. They 
  are also known as 
  “ungulates.” 
  They include 
  deer, zebras, 
  giraﬀes, and camels.
  Nearly all the members of 
  this family of mammals are 
  meat-eaters. They all share 
  certain features, such as 
  sharp cheek teeth for slicing 
  ﬂesh. Most are intelligent 
  animals and many are 
  ruthless killers.
  Humpback whale
  MAMMALS
  FACT FILE
   
  ■ BRAIN BOX 
  All mammals 
  have a large 
  brain relative 
  to their body 
  size. The brain  
  is protected in  
  a hard skull.
   
  ■ Hair Most 
  mammals have hair 
  or fur on their skin 
  to keep them warm.
   
  ■ Young Rather than laying eggs, most 
  mammals give birth to babies and look 
  after them while they grow and learn.
  d SOUTHERN RIGHT WHALE 
  Some whales, like this one, are ﬁlter feeders, 
  sieving plankton from the water through 
  special plates in the mouth.
  d PANDA Not all carnivores are predators. 
  The panda is a member of the carnivore 
  family but it mainly eats plants.
  d RED DEER Many hoofed 
  mammals have horns or antlers. 
  Antlers can grow particularly  
  large on some species of deer.
  . GIRAFFE The world’s 
  tallest mammal can reach 
  more than 17 ft (5 m)  
  in height.
  . HYENA 
  There are four 
  species (types) 
  of hyena, 
  including the 
  striped hyena 
  shown here.
  Tiger
  Zebra
  Jaw
  Tiger’s skull
  Skull
  Teeth
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  218
  MAMMALS
  Pelycosaurs
  Mammals evolved from a group of reptilelike animals 
  called pelycosaurs. The pelycosaurs lived long before even 
  the dinosaurs and for a while were the largest animals on 
  land. They looked more like lizards than mammals, but 
  their link with mammals is clear from a special hole in the 
  skull behind each eye. As in mammals, the jaw muscles 
  passed through this hole, giving these animals a killer bite.
  Caninelike fangs
   
  ■ When  280 million years ago (Early Permian)
   
  ■ Fossil location  Germany, USA
   
  ■ Habitat  Swamps
   
  ■ Length  10 ft (3 m)
   
  ■ Diet  Meat
  Dimetrodon was the most fearsome predator 
  of its time. It was built like a Komodo dragon, 
  but with a huge “sail” on its back formed from 
  skin wrapped over rods of bone. Dimetrodon 
  means “two-sized tooth”—unlike most 
  reptiles, which have teeth that are similar to 
  each other, Dimetrodon had teeth of several 
  types, as mammals have. At the front of the 
  mouth were long, daggerlike canines for 
  piercing and grabbing flesh; at the back were 
  smaller, sharp-edged teeth for slicing flesh.
  u FOSSIL TRACKS These 
  five-toed footprints may have been 
  left by Dimetrodon, one of the 
  most common animals of its time.
  Dimetrodon had a hole 
  in the skull behind each eye 
  socket. Strong jaw muscles went 
  through these holes, giving it a 
  powerful bite. Humans share 
  the same feature.
  FAMILY FACT FILE
  Key features
   
  ■ Cold-blooded
   
  ■ Reproduced by laying eggs
   
  ■ Small brains
   
  ■ Lizardlike, sprawling legs
   
  ■ Short claws on toes
   
  ■ Holes in the skull behind the eyes
   
  ■ Varied teeth
  When
  Pelycosaurs first appeared in the Late 
  Carboniferous, 320 million years ago. 
  They died out in the Late Permian,  
  251 million years ago.
  Dimetrodon
  die-MET-roe-don
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  219
  MAMMALS
   
  ■ When  280 million years ago (Early Permian) 
   
  ■ Fossil location  USA 
   
  ■ Habitat  Swamps 
   
  ■ Length  Skull 2½ in (6 cm) 
   
  ■ Diet  Meat  
   
  ■ When  260 million years ago (Late Permian) 
   
  ■ Fossil location  USA, Russia 
   
  ■ Habitat  Swamps 
   
  ■ Length  3 ft (1 m) 
   
  ■ Diet  Small animals 
   
  ■ When  310–290 million years ago 
  (Late Carboniferous–Early Permian) 
   
  ■ Fossil location  USA 
   
  ■ Habitat  Swamps 
   
  ■ Length  10 ft (3 m) 
   
  ■ Diet  Fish and small animals 
  This large predator had a very long skull and 
  huge jaws packed with 170 sharp, pointed 
  teeth. It was built like a crocodile and may 
  Eothyris
  ee-oh-THY-riss
  Varanops
  VA-ran-ops
  Ophiacodon
  oh-fee-ACK-oh-don
  even have hunted like a crocodile, lurking  
  in swamps or rivers ready to ambush passing 
  prey. However, Ophiacodon is unlikely to 
  have been an underwater hunter, since its tall 
  skull would have been difficult to swing 
  sideways in water, making prey such as fish 
  difficult to catch. On land, Ophiacodon 
  walked with its limbs sprawled like a lizard, 
  dragging its tail behind it.
  Varanops looked like a modern monitor lizard. 
  Compared to other pelycosaurs it was a 
  fast-moving hunter with long legs, well suited 
  to scampering after small animals, which it 
  caught and killed with strong jaws lined with 
  dozens of backward-curved teeth. Varanops 
  lived in the Late Permian and was one of the 
  last of the pelycosaurs.
  Only a single fossil of Eothyris exists: a broad, 
  flat skull that was discovered in 1937. It shows 
  that Eothyris probably had a quick, snapping 
  bite. On each side of the upper jaw were  
  two large fangs. The remaining teeth were 
  smaller but sharply pointed, so Eothyris was a 
  flesh-eater. A small animal, it perhaps hunted 
  insects or reptiles smaller than itself.
  DID YOU KNOW...?
  Running along Dimetrodon’s back was a spectacular “sail” 
  supported by tall rods of bone that grew from its spine. 
  The sail might have been used to help this 
  cold-blooded creature warm its body. In the early 
  morning, Dimetrodon would have been cold and 
  sluggish. Perhaps it basked in the sun, 
  turning its body so the sail caught 
  the sun’s rays. Blood ﬂowing 
  through the sail would have 
  spread the warmth through 
  the rest of the body, helping 
  Dimetrodon become active.
  Sail
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  220
  MAMMALS
  Therapsids
  d EARLY HERDS? Remains of 
  several Moschops individuals have 
  been found fossilized together. Perhaps 
  these plant-eaters lived in small herds 
  for protection from predators.
  FAMILY FACT FILE
  Key features
   
  ■ Stout bodies
   
  ■ Massive heads
   
  ■ Teeth specialized to form incisors, 
  canines, and molars
   
  ■ More upright legs than their 
  pelycosaur ancestors
  When
  Therapsids appeared in the Permian 
  Period and became the dominant animals 
  on land. They went into decline during 
  the age of the dinosaurs, but one family 
  of small therapsids survived and gave rise 
  to the mammals.
  Moschops
  MOE-shops
  During the Permian Period, the pelycosaurs (see previous 
  page) evolved into more mammal-like animals known as 
  therapsids. Unlike their sprawling, lizardlike ancestors, 
  the therapsids had a more upright build that let them 
  run and breathe more easily, allowing a more active 
  lifestyle. The therapsids were the ancestors of mammals 
  and became increasingly mammal-like over time.
   
  ■ When  255 million years ago (Late Permian)
   
  ■ Fossil location  S. Africa
   
  ■ Habitat  Forests
   
  ■ Length  8 ft (3 m)
   
  ■ Diet  Plants
  Moschops was a heavily built plant-eater, 
  about the size of a bear. It had stout legs, a 
  huge, barrel-shaped chest, and a short tail.  
  The bone in the top of its skull was  
  amazingly thick. Scientists think males may 
  have used their massive skulls as battering 
  rams in contests over mates, as bighorn sheep 
  do today. Moschops had wide jaws with short, 
  chisel-like front teeth that met (rather than 
  overlapping) when its mouth closed,  
  allowing it to nip plants precisely.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  221
  MAMMALS
  Broad feet with 
  blunt claws 
  Huge, barrel-shaped body to 
  house large mass of intestines
  Stout limb bones 
   
  ■ When  255 million years ago (Late Permian)
   
  ■ Fossil location  S. Africa
   
  ■ Length  3 ft (1 m)
   
  ■ Diet  Plants 
  Pelanomodon was a member of a 
  large and very successful family  
  of plant-eating therapsids called  
  the dicynodonts (DIE-CYE-no-
  donts). The dicynodonts used 
  toothless beaks to pluck vegetation,  
  and most had a single pair of tusks. 
  Pelanomodon was a stocky, piglike 
  dicynodont that had no tusks. Like other 
  dicynodonts, it could slide its lower jaw forward and 
  backward, which helped it grind the tough plants it ate.
  , FINE FOSSIL 
  In this remarkably 
  well-preserved Pelanomodon 
  skull, the bone around the 
  beak has lots of tiny holes 
  where blood vessels once ran.
  Placerias 
  plah-SEE-ree-ass
  Sinokannemeyeria
  SIGH-no-CAN-eh-my-AIR-ee-ah
  Pelanomodon
  PEL-an-OH-mow-don
  Robertia
  roe-BERT-ee-ah
   
  ■ When  255 million years ago (Late Permian)
   
  ■ Fossil location  S. Africa
   
  ■ Habitat  Woodlands
   
  ■ Length  1 ft (0.4 m)
   
  ■ Diet  Plants
  The earliest dicynodont known from good 
  fossils is Robertia. This small plant-eater was 
  about the size of a domestic cat and had a 
  turtlelike beak, which it used to crop leaves.  
  It had a pair of tusks formed from canine 
  teeth and perhaps used them to dig for roots.
   
  ■ When  220–215 million years ago (Late Triassic) 
   
  ■ Fossil location  USA 
   
  ■ Habitat  Flood plains 
   
  ■ Length  6–11 ft (2–3 m) 
   
  ■ Diet  Plants 
  Placerias was one of the 
  biggest herbivores of its 
  day, weighing about  
  1,300 lb (600 kg). One  
  of the last large dicynodonts,  
  it lived at the same time as early dinosaurs. 
  Similar in shape and weight to a hippo, it 
  might have wallowed in water, too, and  
  may have used its tusks for fights and social 
  displays as hippos do. A find of 40 skeletons 
  in one place suggests Placerias lived in herds.
   
  ■ When  235 million years ago (Middle Triassic)
   
  ■ Fossil location  China
   
  ■ Habitat  Woodland
   
  ■ Length  6 ft (2 m)
   
  ■ Diet  Tough vegetation, roots
  This pig-sized dicynodont had a massive 
  head, a long snout, and a huge belly to 
  house the large intestines needed for 
  digesting rough plant material. Like 
  other dicynodonts, it could move its 
  lower jaw forward and backward to  
  shear and grind tough leaves. Its legs were 
  short and stumpy, with a slightly sprawling 
  gait, suggesting it was not very fast or agile  
  on its feet. But it may have used its powerful 
  forelimbs and small tusks to dig for roots. 
  Pitted beak bone
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  222
  MAMMALS
  The first mammals
  Small and furry, the first mammals looked like mice.  
  They were warm-blooded, which means that their body 
  temperature stayed the same whether it was hot or cold 
  outside. Early mammals lived alongside the dinosaurs 
  but avoided them by hiding in the day and being active 
  only at night, when in the cool, dark air, they chased 
  insects, worms, and other small animals.
   
  ■ When  125 million years ago (Early Cretaceous)
   
  ■ Fossil location  Australia
   
  ■ Habitat  Woodlands 
   
  ■ Length  4 in (10 cm)
   
  ■ Diet  Insects
  Only the lower jaw of Teinolophos has been 
  found. Even so, scientists are fairly sure this 
  small creature was related to the modern 
  duckbilled platypus, the jaw of which shares 
  key features with that of Teinolophos. Most 
  modern mammals give birth to babies, but  
  the duckbilled platypus is one of the few 
  mammals that still lays eggs, as its reptilelike 
  ancestors did. Teinolophos was an 
  egg layer, too.
  Teinolophos
  TIE-nuh-LOW-fuss
   
  ■ When  65 million years ago (Late Cretaceous)
   
  ■ Fossil location  Mongolia
   
  ■ Habitat  Woodlands 
   
  ■ Length  4 in (10 cm)
   
  ■ Diet  Possibly plants
  Nemegtbaatar looked a bit like a vole, with a 
  similar short, deep skull, but it wasn’t a close 
  relative of voles. It had a wide snout, and its 
  snout bones were riddled with tiny holes for 
  blood vessels. Perhaps the extra blood flow 
  supplied a special gland or a patch of sensitive 
  skin on the top of its head. Nemegtbaatar is 
  thought to have been a plant-eater. It had  
  no canine teeth (fangs), and its front 
  teeth (incisors) were large and 
  jutted out, giving it a 
  buck-toothed look.
  Nemegtbaatar
  nem-EGT-bat-or
  FAMILY FACT FILE
  Key features of mammals
   
  ■ Females have glands that produce milk
   
  ■ Body covered with fur or hair
   
  ■ Ears contain tiny bones that evolved 
  from the jaw bones of ancestors
   
  ■ Four different types of tooth
   
  ■ Teeth replaced only once during life
  When
  The first mammals appeared in the Late 
  Triassic, 200 million years ago.
  Teinolophos’s jaw 
  was tiny but it had 
  a strong bite.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  223
  MAMMALS
   
  ■ When  200 million years ago (Late Triassic)
   
  ■ Fossil location  China
   
  ■ Habitat  Woodlands
   
  ■ Length  12 in (30 cm)
   
  ■ Diet  Omnivorous
  Sinoconodon is one of the earliest known 
  mammals. Its ear bones show that it was a 
  mammal, but like a reptile it had teeth that 
  were continuously replaced throughout life.  
  It was about the size of a squirrel and had a 
  slim snout but a strong jaw joint and chin, 
  suggesting a powerful bite—perhaps it  
  preyed on large insects or small reptiles. 
   
  ■ When  190 million years ago 
  (Early Jurassic)
   
  ■ Fossil location  S. Africa
   
  ■ Habitat  Woodlands
   
  ■ Length  4 in (10 cm)
   
  ■ Diet  Insects
  Megazostrodon was 
  built like a shrew, with 
  a slender body and a 
  long snout and tail. Its skeleton was not 
  specialized for any particular lifestyle, but  
  it probably climbed, burrowed, and ran,  
  much like modern rats and shrews. Studies of 
  its braincase indicate it had a relatively large 
   
  ■ When  125 million years ago (Early Cretaceous)
   
  ■ Fossil location  China
   
  ■ Habitat  Woodlands
   
  ■ Length  8 in (20 cm)
   
  ■ Diet  Insects and other small animals
  Only one fossil of Eomaia exists but it 
  is beautifully preserved and shows a thick  
  coat of fur as well as features typical of a good 
  climber, such as a very long tail. Studies of the 
  bones show Eomaia was more closely related 
  to mammals that give birth to well-developed 
  babies than to egg-layers or marsupials.
   
  ■ When  210–180 million years ago 
  Late Triassic to Early Jurassic
   
  ■ Fossil location  Wales, China, USA
   
  ■ Habitat  Woodlands
   
  ■ Length 4 in (9 cm)
   
  ■ Diet  Insects
  Morganucodon was discovered in Wales, where 
  thousands of fossilized teeth and broken bones 
  were found in a quarry. Later, similar fossils 
  were found as far apart as China, South 
  Africa, and North America, suggesting this 
  creature was common and widespread at the 
  Sinoconodon
  SIGH-no-CON-oh-don
  Megazostrodon
  MEG-ah-ZO-stroh-don
  Eomaia
  EE-oh-MY-ah
  Morganucodon
  MORE-gan-oo-CODE-on
  brain and the well-developed hearing 
  and smell of a nocturnal animal (an animal 
  that’s active by night). Its teeth suggest a diet 
  of insects. It probably hunted for insects and 
  other small animals at night and hid from 
  danger during daylight hours.
   
  ■ When  80–70 million years ago (Late Cretaceous) 
   
  ■ Fossil location  Mongolia 
   
  ■ Habitat  Woodlands 
   
  ■ Length  8 in (20 cm) 
   
  ■ Diet  Insects 
  This creature was one of the earliest “placental 
  mammals” (mammals that give birth to 
  well-developed babies). It had a very long, 
  narrow snout and teeth that grew continuously 
  throughout its life, as those of rodents do.  
  Its hindlimbs were longer than its forelimbs, 
  allowing it to hop like a jerboa. Its pointed 
  teeth suggest a diet of insects and maybe seeds.
  Zalambdalestes
  ZAH-lam-da-LESS-tease
  u HAIRY CREATURE Fur evolved as a 
  means of keeping the body warm. It allowed 
  early mammals to stay active at night when 
  cold-blooded reptiles had to rest.
  time of the dinosaurs. A tiny, shrewlike 
  animal, it had short legs and a short tail.  
  It probably laid eggs as reptiles do, and its  
  jaw showed a mixture of mammalian and 
  reptilian features.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  224
  Flowering 
  plants
  It’s hard to imagine a world without 
  ﬂowering plants, but today’s colorful varieties 
  only began to emerge during the last age of 
  the dinosaurs, the Cretaceous Period.
  The beginnings
  The earliest ﬂowering  
  plant yet identiﬁed is 
  Archaefructus sinensis or 
  “ancient fruit,” which was 
  small, low growing, and 
  straggly, and not like the 
  colorful plants of today.  
  It dates back around  
  125 million years.
  When did petals appear?
  Early ﬂowers lacked petals 
  and when they did ﬁrst 
  appear, they were tiny. 
  Petals created more variety, 
  as plants began to compete 
  for attention from insect 
  pollinators.
  What is pollination?
  Most ﬂowering plants 
  don’t produce seeds 
  unless a dustlike 
  substance—pollen—is 
  transferred from one ﬂower to 
  another. Pollen can be carried by 
  wind or by animals such as bees, 
  which are rewarded with nectar.
  , ROBINIA is a ﬂowering 
  tree native to North America. 
  It is also called a locust.
  MAMMALS
  An old friend
  Magnolias color our world today, but they were 
  also familiar to the dinosaurs. They began to 
  appear in the middle of the Cretaceous Period, 
  spreading because they grew quickly, which was 
  a defense against being eaten by dinosaurs.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  225
  They are everywhere
  Today, practically all we eat that isn’t meat comes from a ﬂowering 
  plant, while farmed animals, such as cattle, depend on such plants 
  for nourishment. Even our clothes are made from ﬂowering plants, 
  which are used for making linen and cotton.
  Life in the cold
  Flowering plants can 
  survive in hot deserts or on 
  freezing mountaintops. In 
  the land around the North 
  Pole, where the deep soil  
  is frozen solid, trees can’t 
  survive but small ﬂowering 
  plants cover the ground, 
  forming a landscape called 
  tundra.
  Grasses
  Grasses are ﬂowering plants 
  with tiny ﬂowers that are 
  pollinated by wind. Grasses 
  appeared in the Cretaceous, 
  but grasslands as we know 
  them didn’t really become 
  established until around  
  10 million years ago.
  It’s in the fruit
  After being pollinated, a 
  ﬂower produces seeds. To 
  help seeds disperse to new 
  habitats, many plants wrap 
  them in a fruit. Fruits are 
  often sweet and ﬂeshy to 
  attract animals, which eat 
  the fruit and discard the 
  seeds later in droppings.
  MAMMALS
  d A COLORFUL MEADOW
  Many ﬂowering plants burst into bloom in 
  the spring, when insect pollinators become 
  active as the weather warms up. All the 
  plants you can see in this picture are 
  members of the ﬂowering plant family.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  226
  MAMMALS
  Marsupials
  The earliest mammals reproduced by laying eggs,  
  but by the Cretaceous Period mammals had evolved 
  new ways of reproducing. The marsupials and their 
  close relatives gave birth to tiny babies that developed 
  outside the mother’s body, often in a pouch. Today, 
  most marsupials are found in Australia, but in  
  the past they were very common in South America  
  and Antarctica too.
   
  ■ When  10–2 million years ago (Neogene)
   
  ■ Fossil location  S. America
   
  ■ Habitat  Woodlands
   
  ■ Length  5 ft (2 m)
   
  ■ Diet  Meat
  Thylacosmilus looked just like a saber-
  toothed cat, but it was a close relative of the 
  marsupials. It was the size of a jaguar and  
  built like a cat, but details of its skeleton  
  show it was more like a giant opossum than  
  a member of the cat family. Its huge canine 
  teeth rested on odd-looking bony extensions 
  of its chin, and unlike the teeth of cats they 
  never stopped growing.
  FAMILY FACT FILE
  Key features of marsupials
   
  ■ Give birth to tiny, immature babies
   
  ■ Babies usually develop inside a pouch
   
  ■ Four pairs of molar teeth
   
  ■ Furry or hairy body
   
  ■ Mothers produce milk for young
  When
  Marsupials first appeared in the Early 
  Cretaceous (about 125 million years 
  ago). Today, there are close to 300 
  marsupials, including kangaroos, 
  wombats, and koalas. 
  Thylacosmilus
  THIGH-lah-coe-SMILE-us
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  227
  MAMMALS
   
  ■ When  125 million years ago (Early Cretaceous)
   
  ■ Fossil location  China
   
  ■ Habitat  Woodlands
   
  ■ Length  6 in (15 cm)
   
  ■ Diet  Insects and worms
  Judging by its teeth and by the bones of  
  its wrists and ankles, this chipmunk-sized 
  tree-dweller was closely related to the first 
   
  ■  When  23–2 million years ago 
  (Paleogene–Neogene)
   
  ■ Fossil location  S. America
   
  ■ Habitat  Desert 
   
  ■ Length  1 ft (0.4 m)
   
  ■ Diet  Plants
  Argyrolagus fossils dating back 
  to 53 million years ago 
  have been found in 
  South America. This 
  creature looked like a 
  giant kangaroo rat, with 
   
  ■ When  2 million–40,000 years ago (Neogene)
   
  ■ Fossil location  Australia
   
  ■ Habitat  Forest and scrubland
   
  ■ Length  10 ft (3 m)
   
  ■ Diet  Plants
  Also known as the giant wombat, rhinoceros- 
  sized Diprotodon was the largest marsupial 
  known. A plant-eater, it survived on a 
  mixture of rough leaves and grasses  
  and may have lived in herds. Fossils 
  of female Diprotodons carrying 
  young reveal that babies’ pouches 
  opened toward the rear, unlike  
  the forward-facing pouches of 
  u KILLER TEETH Two long, 
  saber-shaped teeth pointed downward  
  from Thylacosmilus’s upper jaw. They were 
  protected by tooth guards made of bone.
  Sinodelphys
  SIGH-no-DELF-iss
  Argyrolagus
  ar-JYE-roe-LAY-gus
  Diprotodon
  die-PRO-toe-don
  marsupials, although it wasn’t a marsupial itself. 
  The single fossil, found in China in 2003, is 
  well preserved and shows tufts of hair around 
  the bones. Sinodelphys was a good climber, 
  with flexible ankle bones—it could rotate its 
  feet backward to climb down trees. It probably 
  scurried around among the branches—safe 
  from predators—chasing after insects.
  Kangaroos are the largest living marsupials 
  and are found only in Australia and New 
  Guinea. A kangaroo baby (a “joey”) is the 
  size of a jellybean when born and is blind, 
  deaf, hairless, and has no back legs. It 
  squirms into its mother’s pouch 
  and stays there for up to eight 
  months, suckling from 
  a nipple, until 
  it develops 
  fully.
  LIVING RELATIVE
  very long hindlimbs and small 
  forelimbs. It probably moved 
  around by hopping, just like  
  a modern kangaroo. Its long  
  tail helped it to keep its balance. 
  Argyrolagus’s narrow head had a 
  pointed snout with broad cheek teeth, 
  which it may have used for crushing 
  tough plants and other vegetation. 
  This marsupial had big eyes for seeing 
  in the dark and probably fed at night.
  kangaroos. Diprotodon disappeared shortly 
  after humans first colonized Australia. Some 
  scientists think it was hunted to extinction for 
  its meat, though others blame loss of forest as 
  Australia’s climate gradually became more dry.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  228
  MAMMALS
  Thylacine
  Most large extinct animals are known only from fossils. 
  The thylacine, or Tasmanian tiger, is one of the few that 
  was photographed and even ﬁlmed before it vanished. This 
  fascinating animal was a marsupial (a pouched mammal) 
  that evolved the shape, appearance, and lifestyle of a wolf. 
  Thylacines once lived throughout New Guinea, Australia, 
  and Tasmania. The last one died in a zoo in 1936.
   
  ■ When  2 million years ago—1936
   
  ■ Location  Tasmania, Australia, New Guinea 
   
  ■ Habitat  Woodlands
   
  ■ Length  Around 3 ft (1 m) 
   
  ■ Diet  Meat
  Before it disappeared, the thylacine was the 
  largest carnivorous marsupial of modern 
  times. It had a slender, doglike build, dark 
  stripes on a tan-colored back, and a skull 
  remarkably like a wolf’s. Unlike a wolf, 
  however, the thylacine was unable to run  
  fast on all fours, and it had a stiﬀ tail like a 
  kangaroo’s. Unusually for a marsupial, both 
  males and females had pouches. It was 
  nocturnal, hiding in the day and hunting at 
  night for emus, kangaroos, and small animals.
  Thylacine
  THIGH-la-seen
  Last thylacine
  By the early 20th century, thylacines had 
  disappeared from Australia and were perilously 
  rare in Tasmania. But farmers thought they were 
  killing sheep, and the Tasmanian government 
  paid them a bounty of £1 for every one they shot. 
  By the 1930s, only one was left in Hobart Zoo in 
  Tasmania (shown here). It died in 1936. Despite 
  tantalizing claims of sightings since then, the 
  species was oﬃcially declared extinct in 1982.
  542 million years ago
  4.6 billion years ago
  Precambrian Eon
  Cambrian
  Ordovician
  Silurian
  Devonian
  Carboniferous
  299
  359
  416
  444
  488
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  229
  MAMMALS
  u ROCK PAINTINGS made by the aboriginal 
  people of Australia show that thylacines were once 
  widespread on the Australian mainland. 
  The Tasmanian devil is one of the  
  closest living relatives of the thylacine. 
  This cat-sized carnivore is named for  
  its blood-curdling scream and is famous 
  for having an immensely powerful bite 
  that can crush bones. It eats every bit  
  of a carcass—bone, skin, feet, and all. 
  When alarmed, it gives out a foul odor  
  to drive away enemies.
  LIVING RELATIVE
  Permian
  Triassic
  Jurassic
  Cretaceous
  Paleogene
  Neogene
  251
  200
  145
  65
  23
  Now
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  230
  MAMMALS
  Insect-eaters and relatives
  Many early mammals were not carnivores or herbivores 
  but insectivores, surviving on a diet of insects, worms, 
  snails, and other small animals. They had excellent 
  senses of smell and hearing, but often poor vision. They 
  either made burrows in the ground or lived among the 
  trees. Shy and secretive, many were nocturnal, hunting 
  at night when it was safe to venture out.
   
  ■ When  40 million years ago (Paleogene)
   
  ■ Fossil location  Europe
   
  ■ Habitat  Woodlands
   
  ■ Length  3 ft (1 m)
   
  ■ Diet  Insects and other small animals
  Leptictidium had enormous hind legs and might 
  have hopped around like a miniature kangaroo, 
  although it could probably scamper on all fours, too. 
  Studies of its skull suggest it had a long, trunklike 
  nose like that of an elephant shrew. It would have 
  used this to sniff out insects and other small animals. 
  Fossilized stomach contents show it fed not only on 
  insects but also on lizards and small mammals.
  Leptictidium
  LEP-tick-TID-ee-um
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  231
  MAMMALS
  FAMILY FACT FILE
  Many different types of mammal feed 
  on insects. Although these 
  insect-eaters share some key features, 
  they aren’t closely related and don’t 
  make up a true animal family.
  Key features
   
  ■ Coats of fur or hair
   
  ■ Pointed snouts
   
  ■ Short legs
   
  ■ Claws for climbing and digging
   
  ■ When  2 million–10,000 years ago 
  (Neogene)
   
  ■ Fossil location  S. America
   
  ■ Habitat  Swamps
   
  ■ Length  6½ ft (2 m)
   
  ■ Diet  Plants
  Glyptodon was a giant relative of today’s 
  armadillos, but unlike an armadillo it ate plants 
  rather than insects. It was an enormous animal, 
  weighing as much as a small car. Its armor was 
  made up of more than a thousand small, bony 
  Glyptodon
  GLIP-toe-don
   
  ■ When  10–5 million years ago (Late Neogene)
   
  ■ Fossil location  Italy
   
  ■ Habitat  Woodlands
   
  ■ Length  2 ft (0.5 m)
   
  ■ Diet  Probably insects and dead meat
  Although its name means “terrible hedgehog,” 
  Deinogalerix did not have spines like its 
  modern relatives. Instead, its body was covered 
  with hair. With its long, conical snout, small 
  pointed ears, and a tapering tail, it looked 
  more like a giant rat than a hedgehog. 
  Deinogalerix perhaps fed on large insects 
  such as beetles and crickets, but it may also 
  have eaten birds and small mammals, as well 
  as scavenging meat from carcasses. Rather 
  than chasing after prey, it probably rooted 
  through the undergrowth, snapping at  
  any small animal it came across before  
  the victim had time to escape.
  Eurotamandua
  YOU-row-ta-MAN-doo-ah
  Deinogalerix
  DIE-no-GAL-eh-rix
   
  ■ When  50–40 million years ago (Early Paleogene)
   
  ■ Fossil location  Germany
   
  ■ Habitat  Woodlands
   
  ■ Length  3 ft (1 m)
   
  ■ Diet  Ants and termites
  Eurotamandua was a close relative of modern 
  pangolins. Pangolins have no teeth and feed 
  by ripping open ant and termite nests with 
  their claws and collecting insects with a long, 
  sticky tongue. Eurotamandua had no teeth 
  but had a long snout and probably a long 
  tongue, too. It also had a flexible, muscular  
  tail with which it might have gripped  
  branches while climbing.
  Like their ancient relative Glyptodon, 
  armadillos have armor made up of bony plates 
  to protect themselves from predators. Baby 
  armadillos are born with soft shells, which 
  harden as they grow. The three-banded 
  armadillo can roll into a ball to protect its soft 
  underbelly; other armadillo species drop to 
  the ground and pull in their legs.
  LIVING RELATIVE
  plates arranged like tiles over its back and  
  tail. It had a small, helmetlike head and 
  flat-topped teeth for grinding tough leaves.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  Icaronycteris
  Prehistoric bats such as Icaronycteris were not 
  very diﬀerent from the ones found today. They 
  even hunted in the same manner—ﬂying around 
  in the night skies and swooping over places 
  where plenty of insects gathered, such as among 
  the trees or above lakes. Some scientists suggest 
  that these early bats ﬂew at night to escape  
  the clutches of predatory birds that 
  hunted during the day.
  MAMMALS
  DID YOU KNOW...?
  Icaronycteris is named after Icarus, 
  the son of the ancient Greek craftsman 
  Daedalus. According to Greek myth,  
  Icarus and his father escaped from prison 
  on wings attached by wax. Icarus ﬂew  
  too close to the Sun. The wax  
  melted, and he plunged to his  
  death in the sea below.
  Precambrian Eon
  Cambrian
  Ordovician
  Silurian
  Devonian
  Carboniferous
  Permian
  251
  299
  359
  416
  444
  488
  542 million years ago
  4.6 billion years ago
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  233
   
  ■ When  55–50 million years ago (Paleogene) 
   
  ■ Fossil location  USA 
   
  ■ Habitat  Woodlands of N. America 
   
  ■ Length  1 ft (0.3 m) 
   
  ■ Diet  Insects  
  We know Icaronycteris was a night-flying bat 
  that caught prey in midair because moth  
  scales have been found in the stomach of one 
  fossil. To catch moths at night, modern bats 
  send out pulses of sound and use the echoes to 
  “see” in the dark (echolocation). The structure 
  of Icaronycteris’s inner ear suggests it was able 
  to use echolocation, too.
  Icaronycteris
  ICK-ah-roe-NICK-teh-riss
  u ICARONYCTERIS is one of the earliest 
  known bats. Unlike some modern bats, its long 
  tail was not connected to its hindlimbs by a flap 
  of skin. However, it did sleep hanging upside 
  down from a tree branch or a cave roof.
  Bats are the only true ﬂying mammals. They 
  have membranes of skin between their arms 
  and ﬁngers, which have evolved into long 
  wings. Some bats, such as this fruit bat, or 
  ﬂying fox, feed on fruit instead of insects.
  LIVING RELATIVE
  MAMMALS
  Triassic
  Jurassic
  Cretaceous
  Paleogene
  Neogene
  200
  145
  65
  23
  Now
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  234
  MAMMALS
  Cats and hyenas
  Prehistoric cats were just as ferocious as their modern 
  cousins and sometimes a lot bigger. Like modern cats, 
  they had powerful, muscular bodies and sharp teeth  
  for slashing flesh. Cats and hyenas share a common 
  ancestor, and early species show features of both types 
  of animal. The group includes some of the most 
  efficient killers on the planet.
  Eye socket
  Canine tooth 
  with sawlike 
  rear edge
   
  ■ When  5 million to 10,000 years ago (Neogene) 
   
  ■ Fossil location  N. America and S. America 
   
  ■ Habitat  Plains 
   
  ■ Length  6 ft (1.8 m)  
   
  ■ Diet  Meat  
  Smilodon was one of more than 100 species 
  of saber-toothed cat that scientists have 
  discovered. It was a heavy, muscular animal 
  and a predator to be reckoned with, able to 
  wrestle victims to the ground before tearing 
  open their throats. Despite their size, 
  Smilodon’s teeth weren’t strong enough to bite 
  through the back of the neck, as a lion’s can, 
  and would break if they hit bone. Smilodon 
  hunted a variety of prey, including bears, 
  horses, and young mammoths. Fossils have 
  been found together, suggesting it lived and 
  hunted in packs as lions do.
  , SABER TOOTH 
  Smilodon’s canine teeth were 
  more than 10 in (25 cm) long 
  including the root. Like sabers 
  (short swords), they were curved 
  and had extremely sharp edges.
  Smilodon
  SMILE-oh-don
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  235
  MAMMALS
  Strong forelimbs
  Sharp claws
   
  ■ When  12 million–125,000 years ago (Neogene) 
   
  ■ Fossil location  N. America, Africa, Europe, Asia 
   
  ■ Habitat  Woodlands, grassland 
   
  ■ Length  5 ft (2 m) 
   
  ■ Diet  Meat  
  Large and ferocious, Machairodus was a saber-
  toothed cat, although its canines were shaped more 
  like a knife blade than those of Smilodon. Like 
  most early cats, it was an ambush predator, 
  since its legs were too short to sustain a 
  long chase. Species that evolved later 
  and lived on the plains had longer 
  front limbs, which shows that they 
  were traveling farther to hunt  
  and were running after their prey.
   
  ■ When  13–5 million years ago (Neogene) 
   
  ■ Fossil location  Europe, Asia, Africa 
   
  ■ Habitat  Plains 
   
  ■ Length  4 ft (1.2 m) 
   
  ■ Diet Insects 
  Ictitherium was an early member of the hyena 
  family. However, with its long body and short 
  legs, it looked more like a civet (a tree-climbing, 
  nocturnal mammal) than a modern hyena. It 
  was probably an insect-eater, but may have  
  also fed on small mammals and lizards. 
   
  ■ When  2 million–10,000 years ago (Neogene) 
   
  ■ Fossil location  Europe, Asia 
   
  ■ Habitat  Grassland 
   
  ■ Length  5 ft (2 m) 
   
  ■ Diet  Meat  
  A hunter and scavenger,  
  the cave hyena fed on wild 
  horses, woolly rhinos, deer, 
  and humans in ice age 
  Europe and Asia. Recent 
  tests of DNA from fossils 
  show it was the same species 
  as the modern African 
  spotted hyena (Crocuta 
  crocuta), but larger and 
  with longer legs.
   
  ■ When  5–1 million years ago (Neogene) 
   
  ■ Fossil location  Africa, Europe, Asia, N. America 
   
  ■ Habitat  Woodlands
   
  ■ Length  5 ft (2 m) 
   
  ■ Diet  Meat  
  Dinofelis (“terrible cat”) was about the same 
  size as modern forest-dwelling cats, such as 
  leopards and jaguars. Like these cats, it  
  may even have had a spotted or striped  
  coat that helped it to remain hidden in the 
  undergrowth while it kept a lookout for prey. 
  Dinofelis stalked its prey in the forest, hiding 
  FAMILY FACT FILE
  Key features
   
  ■ Sharp teeth
   
  ■ Powerful jaws and neck muscles
   
  ■ Strong forelimbs
   
  ■ Clawed feet
  When
  The first catlike mammals lived about  
  35 million years ago, in the Paleogene 
  Period. They evolved into the family  
  of modern cats that include lions  
  and jaguars.
  Machairodus
  mah-CARE-oh-duss
  Ictitherium
  ICK-tee-theeri-um
  Cave hyena
  cave high-EE-na
  Dinofelis
  DIE-no-FEE-liss
  behind trees before ambushing victims. 
  Its prominent front teeth 
  were shorter and less 
  flattened than those of 
  other saber-toothed cats 
  but were just as deadly. 
  In Africa, its bones have 
  been found near the sites 
  of early humans, which 
  suggests that it may have 
  preyed on them, too.
  Canine tooth
  Bladelike tooth
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  236
  Ice age!
  Imagine a world in which ice extends farther 
  than the Arctic and Antarctic—a world in 
  which ice sheets cover large chunks of North 
  America, Europe, and Asia. At times, much 
  of the Earth’s surface has been covered by 
  sheets of ice. These periods of Earth’s history 
  are known as its ice ages, with glaciers a 
  prominent feature.
  WHAT IS A GLACIER?
  A glacier is a slow-moving river of  
  ice, forced to move downhill by its 
  weight. It can be enormous. In an ice 
  age, Earth’s temperature varies, with 
  glaciers pushing forward over land 
  during the cold periods (known as 
  glacial periods) and retreating in 
  warmer periods (interglacial periods).
  An unusual route opens
  During an ice age, sea levels fall by as much as 300 ft  
  (100 m) as water becomes locked up on land as ice, instead 
  of ﬂowing out to sea in rivers. As the sea falls, new land 
  appears, sometimes forming a bridge between continents or 
  islands. During the last ice age, land bridges joined Britain to 
  Europe, New Guinea to Australia, and Siberia to Alaska, 
  allowing people to cross from Asia to North America.
  Snowball Earth
  Over millions of years, Earth 
  has moved from warm periods 
  to cold periods and back to 
  warm periods. Scientists don’t 
  know what triggers an ice age, 
  but think it has something to 
  do with gradual changes in the 
  Earth’s orbit around the Sun 
  over millions of years.
  Paciﬁc Ocean
  Arctic Ocean
  Human migration
  Asia
  North 
  America
  During the most severe ice ages, 
  Earth was entirely covered in ice.
  u AN EARLY VIEW A nineteenth century artwork by a 
  Swedish geologist and naturalist, Oswald Heer, provided an 
  unrealistic picture of large mammals, including mammoths 
  and deer, surviving at the edges of the last ice age. In reality, 
  these mammals lived on steppes (grasslands).
  MAMMALS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  237
  Clues from the past
  When an ice age ends and glaciers disappear, they leave behind 
  lots of clues that the land was once buried under ice. Glaciers 
  carve away land as they ﬂow, forming deep, U-shaped valleys. 
  When they melt, they leave behind huge boulders, called 
  erratics, often made from a type of rock not found locally.
  Glacial boulders are known as 
  “erratics.” Some are small, but 
  they can also be huge.
  DID YOU KNOW?
  Modern humans emerged during the last 
  ice age, living south of the ice sheets.  
  There were also big mammals known as 
  megafauna, including:
   
  ■ Woolly mammoths 
   
  ■ Woolly rhinos 
   
  ■ Cave bears 
   
  ■ Cave lions 
   
  ■ Giant beavers  
  Many of the large mammals became extinct 
  just after modern humans arrived. 
  A blanket of ice
  At the peak of the last ice age, some 
  20,000 years ago, large areas of 
  northern Europe were covered by ice, 
  as well as Greenland and Iceland and 
  parts of the Atlantic Ocean. 
  Europe’s mountain ranges—the 
  Alps, the Pyrenees, the Urals, 
  and the Carpathians—were 
  also covered in ice.
  u ICE SHEET 
  Northern Europe was 
  covered by a gigantic 
  ice sheet during the 
  last ice age.
  MAMMALS
  Ice age
  Today
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  FAMILY FACT FILE
  Key features
   
  ■ Long snouts
   
  ■  Four shearing teeth at front of jaw 
  (carnassials)
   
  ■ Walked on all fours
   
  ■  Most were unable to retract (pull back) 
  their claws into a protective sheath, as 
  cats can do.
  When
  They first appeared in the Paleogene 
  Period (about 55 million years ago), and 
  still exist today.
  MAMMALS
  Caniforms
  This family of mostly carnivorous mammals includes 
  dogs, bears, foxes, raccoons, weasels, and—perhaps 
  surprisingly—seals, sea lions, and walruses, which 
  evolved from bearlike ancestors. Caniform means 
  “dog-shaped,” but early caniforms were tree-climbing 
  animals that resembled pine martens. As they colonized 
  the ground they evolved into more dog- and then 
  bearlike forms. 
   
  ■ When  2 million–10,000 years ago (Late Pleistocene)
   
  ■ Fossil location  Canada, USA, Mexico
   
  ■ Habitat  Plains
   
  ■ Length  5 ft (1.5 m)
   
  ■ Diet  Meat
  Canis dirus (“dire wolf”) was a large animal 
  with much stronger jaws and bigger teeth  
  than modern wolves. Its limbs were shorter 
  than those of its cousin the gray wolf, so it 
  probably spent more time scavenging than 
  hunting. The dire wolf died out in the last  
  ice age, possibly because of the extinction  
  of the large herbivores on which it fed. 
  Thousands of fossils have been found in  
  La Brea tar pits in California (see page 240), 
  suggesting it was a pack hunter.
  Canis dirus
  CAY-niss DIE-russ
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  239
  MAMMALS
   
  ■ When  2 million–10,000 years ago (Late Pleistocene)
   
  ■ Fossil location  Canada, USA, Mexico
   
  ■ Habitat  Mountains and woodlands
   
  ■ Length  10 ft (3 m)
   
  ■ Diet  Omnivorous
  This huge predator was the largest bear ever 
  known. When it reared up on its hindlimbs,  
  it was more than twice the height of a man. 
  Arctodus charged at prey such as deer, bison, 
  and horses, outrunning them on its long legs. 
  It also ate plant foods 
  and probably 
  scavenged on 
  carcasses, too.
  Arctodus
  ARK-toe-duss
   
  ■ When  30–20 million years ago (Neogene)
   
  ■ Fossil location  N. America, Spain, Germany, France
   
  ■ Habitat  Plains
   
  ■ Length  6½ ft (2 m)
   
  ■ Diet  Omnivorous
   
  ■ When  55 million years ago (Paleogene)
   
  ■ Fossil location  Europe, N. America
   
  ■ Habitat  Tropical forests
   
  ■ Length  1 ft (0.3 m)
   
  ■ Diet  Small mammals, reptiles, birds
  Miacis was a member of the family from 
  which all modern carnivorous mammals 
  evolved. A small animal about the size of a 
  weasel, it had a similarly slender body and 
  short legs. Miacis lived high up in trees, using 
  its agile limbs to climb. Its long tail helped it 
  balance as it leaped from branch to branch.  
  It probably hunted smaller animals, such as 
  small mammals and reptiles, using its sharp 
  teeth to tear off flesh in a scissorlike action.  
  It might also have eaten eggs and fruit.  
  Its vision, though good, was not as  
  sharp as that of modern dogs.
   
  ■ When  20 million years ago (Neogene)
   
  ■ Fossil location  USA
   
  ■ Habitat  Coasts
   
  ■ Length  3 ft (1 m)
   
  ■ Diet  Fish, meat, 
  shellﬁsh
  Enaliarctos 
  was one of the 
  earliest members of  
  the pinniped family, which  
  includes seals, sea lions, and 
  walruses. It seems to have divided 
  its time between water and land, 
  rather like a modern sea lion does. With 
  its webbed feet and flippers, Enaliarctos 
  Amphicyon
  am-fee-SIGH-on
  Miacis
  me-AH-kiss
  Enaliarctos
  en-AL-ee-ARK-toss
  Also called a bear-dog, 
  Amphicyon looked like 
  a cross between a dog 
  and a bear. But its 
  large build—it was 
  the size of a modern 
  grizzly bear—and diet of 
  plants and meat made it more like a  
  bear than a dog. It had wolflike teeth, 
  powerful limbs, and a long tail. Since it 
  was too heavily built to chase prey over 
  long distances, it probably 
  ambushed victims, charging 
  and killing them with its 
  powerful jaws and teeth.
  Powerful  
  jaw with a 
  strong bite
  . SURE-FOOTED 
  The needle-sharp 
  claws on Miacis’s 
  toes helped it to  
  hold onto trees  
  as it climbed.
  swam easily through water, although it was 
  more clumsy on land. Its large eyes helped  
  it to see in deep water, and it had specialized 
  inner ears for hearing underwater. Its teeth 
  were well suited to slicing through flesh, and  
  it probably returned to the shore to eat the 
  fish or shellfish it caught.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  240
  MAMMALS
  A sticky end
  Thirty-eight thousand years ago, a pack of 
  saber-toothed cats were pursuing a weak mammoth. 
  The mammoth stumbled into what it thought was a 
  shallow pool, and found itself trapped in sticky tar. 
  The cats were soon trapped, too. Hunted and hunters 
  died. They had fallen into a massive tar pit.
  DID YOU KNOW?
  A tar pit is more correctly known as an 
  asphalt pit (asphalt is naturally occurring, 
  whereas tar is made by people). It is a place 
  where asphalt leaks to the ground’s surface.  
  Asphalt pits have proved valuable in 
  studying ecosystems that existed thousands 
  of years ago because of the animals caught 
  and preserved in them.
  Many of the species found 
  at La Brea are still there 
  today, including the 
  California condor.
  LA BREA 
  Thousands of fossilized animal bones have 
  been found at the La Brea Tar Pits in Los 
  Angeles, many dating back to the last ice age. 
  There are also huge quantities of fossilized 
  plants and insects—altogether these pits have 
  provided a fascinating view of life in the Los 
  Angeles area some 38,000 years ago. 
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  241
  MAMMALS
  MORE PREDATORS THAN PREY?
  One interesting fact shown by the fossils at La Brea 
  is that more than 90 percent of the mammals are 
  carnivores. Why? Perhaps it’s because if a single 
  herbivore became trapped, its struggles would draw 
  predators and scavengers hoping for an easy meal, 
  who in turn became trapped. 
  u SKULLS More than 4,000 dire wolves have been discovered in 
  La Brea tar pits. Dire wolves became extinct some 10,000 years ago.
  Altogether, more than  
  3.5 million specimens have 
  been recovered from La Brea, 
  representing nearly 650 species 
  of plant and animal.
  All these animals have  
  been found at La Brea.
  Herbivores
   
  ■ Mammoth
   
  ■ American mastodon
   
  ■ Ground sloth
   
  ■ Shasta ground sloth
   
  ■ Ancient bison
   
  ■ American camel
   
  ■ Stilt-legged llama
   
  ■ Horse
   
  ■ Pronghorn
   
  ■ Tar-pit pronghorn
   
  ■ California tapir
   
  ■ Elk (wapiti)
   
  ■ Deer
  Carnivores
   
  ■ Short-faced bear
   
  ■ Brown bear
   
  ■ Black bear
   
  ■ American lion
   
  ■ Saber-toothed cat 
  (Smilodon)
   
  ■ Jaguar
   
  ■ American cheetah
   
  ■ Cougar
   
  ■ Dire wolf
   
  ■ Gray wolf
   
  ■ Coyote
   
  ■ Weasel 
  Birds
   
  ■ California condor
   
  ■ Eagle
   
  ■ Hawk
   
  ■ Falcon
   
  ■ Vulture
   
  ■ Sandhill crane
   
  ■ Canada goose
   
  ■ Mallard duck
   
  ■ Night heron
   
  ■ La Brea stork
   
  ■ Grebe
   
  ■ Cormorant
   
  ■ Magpie
   
  ■ Great horned owl
   
  ■ La Brea owl
   
  ■ Greater roadrunner
   
  ■ Band-tailed pigeon
   
  ■ Curlew
   
  ■ California quail
  Reptiles, amphibians,  
  and fish
   
  ■ Kingsnake
   
  ■ Garter snake
   
  ■ Pond turtle
   
  ■ Rainbow trout
   
  ■ Rattlesnake
   
  ■ Salamander
   
  ■ Three-spined stickleback
   
  ■ Tree frog
   
  ■ Toad
  FACT FILE
  uWHAT A MAMMOTH 
  FIND! More than 60 species of 
  mammal have been found at  
  La Brea, including some ﬁne 
  specimens of mammoths. A special 
  museum houses the ﬁnds.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  242
  MAMMALS
  Rabbits and rodents
  Rodents—which include rats, mice, and 
  squirrels—were as plentiful in prehistoric  
  times as they are today. Rabbits, too, hopped 
  and jumped across the landscape in much  
  the same way as their modern descendants. 
  Although most were small herbivores, some 
  species grew to a scarily large size.
   
  ■ When  3 million–10,000 years ago (Neogene)
   
  ■ Fossil location  N. America
   
  ■ Habitat  Lakes, ponds, swamps
   
  ■ Length  10 ft (3 m)
   
  ■ Diet  Plants
  Also known as the giant beaver, 
  Castoroides was about the size of a black 
  bear and was one of the largest rodents 
  ever to have lived. Modern beavers have 
  chisel-like front teeth, but Castoroides’s 
  teeth were broad and large. It had 
  shorter hindlimbs, but its tail was 
  longer and narrower. Like modern 
  beavers, it lived in or near water and 
  perhaps built small dams and dome-
  shaped lodges (beaver homes).
   
  ■ When  25 million years ago (Paleogene)
   
  ■ Fossil location  USA, Japan
   
  ■ Habitat  Woodlands
   
  ■ Length  15 in (38 cm)
   
  ■ Diet  Plants
  Palaeocastor was a much smaller and earlier 
  beaver than Castoroides. This land-dwelling 
  animal dug deep burrows with its front teeth 
  Castoroides
  CASS-tore-OY-deez
  Palaeocastor
  PAY-lee-oh-CASS-tor
  rather than building dams and 
  lodges. Fossilized burrows with 
  Palaeocastor skeletons and tooth 
  marks on the walls were found in 
  1891. These famous burrows were 
  called “devil’s corkscrews” because 
  of their narrow, spiral shape.
  20,000-year-old 
  fossil tooth of a 
  giant beaver.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  243
  MAMMALS
   
  ■ When  10–5 million years ago (Neogene)
   
  ■ Fossil location  Canada, USA
   
  ■ Habitat  Woodlands
   
  ■ Length  12 in (30 cm)
   
  ■ Diet  Plants
  Known as the horned gopher, Ceratogaulus 
  is the smallest mammal known to have had 
  horns and one of the only horned rodents. 
  Scientists once thought that it used its horns 
  for digging, but their position on the skull 
  makes this unlikely. Both sexes had horns,  
  so they were probably used for defense rather 
  than mating displays. Ceratogaulus lived in 
  burrows that it dug with its large claws.  
  Its eyes were small and its vision was  
  probably poor.
   
  ■ When  33–23 million years ago (Late Paleogene)
   
  ■ Fossil location  USA
   
  ■ Habitat  Plains and woodlands
   
  ■ Length  4 in (10 cm)
   
  ■ Diet  Grass
  Palaeolagus is one of the oldest known fossil 
  rabbits. It had long, pointed ears and a slightly 
  longer tail than modern animals. Its hindlimbs 
  were shorter than those of living rabbits, 
  which suggests that it scampered like a squirrel 
  rather than hopping. It had two pairs of upper 
  teeth to nibble on grass and other plants.
   
  ■ When  25 million years ago (Paleogene)
   
  ■ Fossil location  France, Germany, Spain, Turkey
   
  ■ Habitat  Woodlands
   
  ■ Length  10 in (25 cm)
   
  ■ Diet  Plants
  This small rodent could glide through  
  the air. Many Eomys skeletons have 
  been found, showing that it had 
  a long skin membrane 
  between its front and 
  back legs, rather like 
  that of a modern 
  FAMILY FACT FILE
  Key features
   
  ■  Rodents have four special incisor 
  teeth that are used for gnawing; 
  rabbits have eight.
   
  ■ Furry coats
   
  ■ Clawed toes
  When
  They first appeared in the Paleogene 
  Period (about 65 million years ago) 
  and still exist today.
  Ceratogaulus
  seh-RAT-oh-GAWL-us
  Palaeolagus
  PAY-lee-oh-LAG-us
  Eomys
  EE-oh-miss
  flying squirrel. Eomys is thought to 
  be a close relative of gophers and 
  pocket mice that exist today.
  Pair of straight 
  horns
  Sturdy 
  forelimbs
  Skull
  Short 
  hindlimbs
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  Hoofed mammals
  Hooves are simply enlarged toenails that support  
  an animal’s weight and help it walk on hard ground. 
  All hoofed mammals evolved from ancestors with  
  five toes, but over time some toes withered away, 
  leaving just one, two, or three main hooves per foot. 
  Early hoofed mammals were as small as cats, but later 
  species grew to a huge size on a diet of grass or leaves.  
  FAMILY FACT FILE
  Key features
   
  ■ Most were plant eaters
   
  ■ Walked and ran on four legs
   
  ■ Toes with hooves
   
  ■ Large teeth to grind vegetation; some 
  also had tusks
   
  ■ Some had horns
  When
  Hoofed mammals first appeared in the 
  Paleogene Period (about 65 million years 
  ago). Most lived in forests or grasslands.
  MAMMALS
   
  ■ When  38–30 million years ago (Paleogene)
   
  ■ Fossil location  N. America, Asia
   
  ■ Habitat  Plains
   
  ■ Length  10 ft (3 m)
   
  ■ Diet  Plants
  When Native Americans of the Sioux tribe  
  in the United States found the huge fossilized 
  bones of Megacerops in the ground, they 
  thought they were the remains of mythical 
  creatures that galloped across the clouds 
  causing storms, and so named them “thunder 
  horses.” Megacerops was indeed a relative of 
  the horse, but in build and size it was more 
  like a modern rhinoceros and was probably 
  covered in thick hide. The bones above its 
  shoulders bore long spines to support its 
  huge neck muscles and heavy head. 
  Megacerops
  MEG-a-SEH-rops
  Feeding habits
  Megacerops’s teeth suggest it ate soft 
  plants rather than rough vegetation.  
  It may have had a long tongue and 
  flexible lips to choose plants with care.
  Y-shaped horns with blunt 
  ends, which may have been 
  used for display
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  245
   
  ■ When  23 million years ago (Paleogene)
   
  ■ Fossil location  USA
   
  ■ Habitat  Deserts, prairies
   
  ■ Length  3 ft (1 m)
   
  ■ Diet  Plants
  Mesoreodon was a sheep-sized 
  hoofed mammal with big eyes. 
  One fossil was found with its voicebox 
  preserved. Studies of the voicebox reveal that 
  Mesoreodon could make loud, hooting sounds 
  like modern howler monkeys—perhaps to 
  frighten predators and warn members of its 
  herd. It had sharp canine teeth that were 
  probably used to defend against attacks,  
  Mesoreodon
  ME-zoe-REE-oh-don
  or for display. The teeth at the back of the 
  mouth had crescent-shaped edges, suitable  
  for chewing low-growing plants. 
  MAMMALS
   
  ■ When  45–40 million years ago (Paleogene)
   
  ■ Fossil location  N. America, Asia
   
  ■ Habitat  Plains
   
  ■ Length  10 ft (3 m)
   
  ■ Diet  Plants
  Uintatherium was another rhinoceros-like 
  mammal, with a large, barrel-shaped 
  body. Its skull was large and flat, but its 
  brain was very small. On its head were 
  three pairs of horns covered in skin, 
  with the biggest horns at the back. Male 
  Uintatheriums had larger horns than 
  females, which suggests that they used them 
  for display or for fighting other males. The 
  animal’s great weight and short legs suggest it 
  usually moved slowly, although it may have 
  been capable of short bursts of speed.
  Uintatherium
  WIN-tah-THEE-ree-um
   
  ■ When  55–45 million years ago (Paleogene)
   
  ■ Fossil location  N. America, Europe
   
  ■ Habitat  Grasslands, open woodlands
   
  ■ Length  3 ft (1 m)
   
  ■ Diet  Grass
  Like horses, Phenacodus had a 
  skeleton well suited to 
  running. In fact, 
  experts once 
  thought it was an 
  ancestor of the 
  horse. It had 
  longer, more flexible legs than other 
  primitive hoofed mammals and carried 
  most of its weight on its three middle toes. 
  Its large, squarish teeth were ideal for 
  grinding up tough vegetation. 
  Phenacodus
  fen-ACK-oh-duss
  Phenacodus may have had a striped or spotted 
  coat to blend in with woodland undergrowth 
  and help it hide from predators.
  Large, blunt 
  horns
  Tusklike teeth
  Five toes, each ending 
  in a blunt claw
  Long, 
  flexible tail
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  246
  Leptomeryx
  Herds of tiny, deerlike mammals known as Leptomeryx 
  fed in the forests and grasslands of North America for 
  more than 13 million years. Leptomeryx was not 
  much bigger than a hare and probably just as 
  nimble, darting around on its tiny hooves  
  in the undergrowth. This little plant- 
  eater ﬂourished in huge numbers  
  and was probably an easy snack  
  for predators of the time.
   
  ■  When  38–25 million years ago 
  (Paleogene) 
   
  ■ Fossil location  USA
   
  ■ Habitat  Grasslands
   
  ■ Length  1 ft (0.3 m)
   
  ■  Diet  Mostly plants
  Leptomeryx was a ruminant—a 
  hoofed mammal that brings up 
  food from its stomach to chew a 
  second time. During the period in 
  which it lived, the climate changed 
  and grasslands replaced forest. 
  Fossils show that the teeth of 
  Leptomeryx became stronger at the 
  same time—perhaps it was evolving 
  to live on rougher foods such as grass, 
  which contains tiny ﬂecks of glass  
  to protect itself from herbivores. 
  Leptomeryx was built like a deer but 
  had no antlers, although males had small 
  tusks formed from their canine teeth.
  Leptomeryx
  LEP-toe-MERRIX
  MAMMALS
  359
  416
  444
  488
  542 million years ago
  4.6 billion years ago
  Precambrian Eon
  Cambrian
  Ordovician
  Silurian
  Devonian
  Carboniferous
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  247
  Chevrotains (also called mouse deer) are 
  found in the rainforests of Southeast Asia 
  and Africa. Although it’s not clear whether 
  they are close relatives of Leptomeryx, 
  they are about the same size and, like 
  Leptomeryx, lack horns or antlers but have 
  small tusks. These deerlike animals usually 
  live in pairs.
  LIVING RELATIVE
  On their toes
  Hoofed mammals are divided into 
  two groups depending on how 
  many toes they have. Horses, 
  rhinos, and tapirs have an odd 
  number of toes; antelopes, 
  deer, hippos, and pigs have 
  an even number of toes. 
  MAMMALS
  251
  299
  200
  145
  65
  23
  Now
  Permian
  Triassic
  Jurassic
  Cretaceous
  Paleogene
  Neogene
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  248
  MAMMALS
  Macrauchenia 
  DID YOU KNOW...?
  When he was in his twenties, the English scientist 
  Charles Darwin spent two years traveling around 
  the world on the ship HMS Beagle. He came 
  across many exotic plants and animals. In 1834, 
  on a stopover in Argentina, South America, he 
  found a half skeleton of what appeared to be 
  some kind of prehistoric camel or llama. In fact,  
  it was the ﬁrst fossil of Macrauchenia. 
  Precambrian Eon
  Cambrian
  Ordovician
  Silurian
  Devonian
  Carboniferous
  299
  359
  416
  444
  488
  542 million years ago
  4.6 billion years ago
  Seven million years ago, this odd-looking herbivore was 
  common on the plains of South America. It looked like  
  a mixture of different animals, with a body like a horse’s, 
  a long neck like a camel’s, and perhaps even a short 
  trunk. Macrauchenia belonged to an extinct family 
  of hoofed mammals that existed only in South America 
  and Antarctica. 
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  249
  The snout may 
  have looked like  
  a short trunk.
  MAMMALS
  Permian
  Triassic
  Jurassic
  Cretaceous
  Paleogene
  Neogene
  251
  200
  145
  65
  23
  Now
   
  ■ When  7 million–20,000 years ago (Neogene)
   
  ■ Fossil location  S. America
   
  ■ Habitat  Grasslands
   
  ■ Length  10 ft (3 m)
   
  ■ Diet  Leaves and grass
  Macrauchenia’s nostrils were high up on its 
  skull, between the eyes, leading some experts 
  to suggest that it had a short trunk. Its long 
  neck would have allowed it to feed on trees  
  as well as grazing on the ground. Short thigh 
  bones imply it was not a fast runner, but its 
  leg bones were arranged in such a way as to 
  allow it to twist and turn when running, 
  helping it outfox predators such as the 
  saber-toothed cat Smilodon.
  Macrauchenia
  mack-row-KAY-nee-ah
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  250
  Horses
  The earliest horses were small, leaf-eating mammals 
  that lived in forests. Around 20 million years ago, 
  Earth’s climate changed and grasslands began to 
  replace forests. Horses moved to the open plains 
  and adapted to a diet of grass. They grew larger  
  and their legs became longer, making them swifter 
  on their feet. Hundreds of different prehistoric 
  horse species have been found all over the world. 
  They show that the evolution of the horse was like  
  a tree, with many dead ends.
   
  ■ When  23–2 million years ago (Neogene)
   
  ■ Fossil location  N. America, Europe, Asia, Africa
   
  ■ Habitat  Grasslands, plains
   
  ■ Length  5 ft (2 m)
   
  ■ Diet  Leaves and grass
  With its long muzzle and slender legs, the 
  lightly built Hipparion resembled a modern 
  pony. Unlike horses today, which have only 
  one toe on each foot, it had three. Its full 
  weight was borne on its large middle toe, 
  which ended in a hoof. The other toes did not 
  touch the ground, so the feet sprung off the 
  ground quickly, helping 
  the animal to run faster.
  Hipparion
  hip-AH-ree-on
  u GRASS-EATER Hipparion 
  lived on grassy plains. Horses never 
  fully evolved the ability to digest 
  grass. As a result, their manure is 
  full of undigested stalks.
  MAMMALS
  FAMILY FACT FILE
  Key features
   
  ■ Long, narrow heads
   
  ■ Long necks
   
  ■ Slender legs
   
  ■ Large teeth
   
  ■ Hoofed feet, with odd numbers of toes 
  (some had one toe, others three)
  When
  Horses first appeared in the Paleogene 
  Period, 54 million years ago.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  251
  One-toed 
  foot
  Skull similar to 
  modern horse
   
  ■ When  52–45 million years ago (Paleogene)
   
  ■ Fossil location  USA
   
  ■ Habitat  Woodlands
   
  ■ Length  1 ft (0.3 m)
   
  ■ Diet  Plants
  One of the earliest known horses, tiny 
  Protorohippus was a forest-dwelling animal 
  that perhaps lived on its own or in pairs, 
  mostly eating leaves rather than grass. It had 
  very short limbs, with hind legs slightly  
  longer than its fore legs, which suggests that it 
  was a good jumper. Of its three toes, the 
  middle one was enlarged and carried the 
  weight of the animal.
  Protorohippus
  PRO-tore-oh-HIP-us
   
  ■ When  17–10 million years ago (Neogene)
   
  ■ Fossil location  USA, Mexico
   
  ■ Habitat  Plains
   
  ■ Length  3 ft (1 m)
   
  ■ Diet  Grass
  Merychippus
  MEH-ree-KIP-us
   
  ■ When  12–2 million years ago (Neogene)
   
  ■ Fossil location  USA
   
  ■ Habitat  Plains
   
  ■ Length  3 ft (1 m)
   
  ■ Diet  Plants
  Until recently, scientists thought Pliohippus 
  was the ancestor of modern horses, partly 
  because it walked on single-toed feet. 
  However, it had curved teeth (other horses 
  had straight teeth) and strange depressions  
  on its face. With its long, slender limbs, 
  Pliohippus was built for speed.
  Pliohippus
  PLY-oh-HIP-us
   
  ■  When  40–30 million years 
  ago (Paleogene)
   
  ■ Fossil location  USA
   
  ■ Habitat  Woodlands
   
  ■ Length  2 ft (0.5 m)
   
  ■ Diet  Plants
  Mesohippus (“middle horse”) had 
  features of both early and later horses. Like 
  modern horses, it had a long snout with a gap 
  between its front and back teeth. A fast 
  runner, its long, slender legs resembled those 
  of today’s horses, except that Mesohippus’s feet 
  had three toes. It probably fed on bushes and 
  trees, chewing the leaves with teeth smaller  
  than those of grass-eating horses.
  Mesohippus
  MEE-zoe-HIP-us
   
  ■ When  4 million years ago to now (Neogene)
   
  ■ Fossil location  Worldwide
   
  ■ Habitat  Plains and grasslands
   
  ■ Length  9 ft (3 m)
   
  ■ Diet  Grass
  Equus
  ECK-wuss
  Modern horses are large, fast-running 
  mammals with slender legs ending in 
  single-toed, hoofed feet. They have long 
  heads, long tails, and manes of hair on the 
  neck. Today, there are more than 400 breeds 
  of domestic horse but only seven wild 
  species, including zebras and onagers.
  LIVING RELATIVE
  Merychippus was the ﬁrst horse thought to 
  have fed only on grass, unlike its leaf-eating 
  ancestors. It was also the ﬁrst to have a head 
  similar to a modern horse’s, with a long  
  muzzle, deep jaws, and eyes set on either side 
  of its head. Its neck was long, so it was able to 
  graze on grass comfortably. Merychippus lived 
  in large herds, traveling long distances to  
  feed. It could run fast on its long legs,  
  even breaking into a gallop when chased  
  by predators.
  The name Equus includes all modern horses, 
  from racehorses and domestic donkeys to wild 
  zebras. Outside Africa, wild horses are now 
  rare. Equus horses clearly show the much 
  bigger brains that are typical of later 
  mammals. Medium to large in size, they have 
  long heads and long, maned necks. They can 
  run fast, especially when threatened, and live 
  in herds.
  Teeth
  Long, slender legs
  MAMMALS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  252
   
  ■ When  15–5 million years ago (Neogene)
   
  ■ Fossil location  Europe, Asia, Africa
   
  ■ Habitat  Plains
   
  ■ Length  6½ ft (2 m)
   
  ■ Diet  Plants
  Taller than a grizzly bear, this animal 
  had a horselike head, long, clawed 
  forelimbs, and stout hind legs that bore 
  its immense body weight. When fossils 
  of its claws were first discovered, 
  scientists thought it was a type of 
  carnivore. Further research showed it 
  was actually a plant-eating mammal that 
  first appeared during the Neogene 
  Period, 15 million years ago.
  Chalicotherium
  CHA-lih-co-THEE-ree-um
  Chalicotherium
  Chalicotherium was a bizarre hoofed mammal that 
  looked like a cross between a horse and a gorilla. Its 
  front hooves had evolved into massive, hooklike 
  claws, which it probably used to pull branches down 
  from trees so it could reach the leaves. When not on 
  the move, Chalicotherium sat on its haunches feeding. 
  It may also have been able to rear up on its hind  
  legs to reach the highest branches. Its odd-toed  
  feet show that it was a distant relative of  
  horses and rhinos. 
  MAMMALS
  Precambrian Eon
  Cambrian
  Ordovician
  Silurian
  Devonian
  Carboniferous
  359
  416
  444
  488
  542 million years ago
  4.6 billion years ago
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  253
  Pebble beast
  Chalicotherium means “pebble beast.” The 
  animal was so named because the first fossil 
  teeth looked like pebbles. When 
  Chalicotherium became an adult, it shed the 
  teeth at the front of its mouth, leaving only 
  fleshy lips and gums to strip leaves from 
  branches. Mouthfuls of leaves were then 
  ground to a pulp with teeth at the back  
  of the mouth.
  MAMMALS
  , KNUCKLE WALKER This 
  animal’s front legs were much longer 
  than its hind legs. Each front leg 
  ended in long, curved claws, which 
  meant that Chalicotherium couldn’t 
  place its foot flat on the ground. So,  
  it probably shuffled along on its 
  knuckles, just like gorillas do today.
  Permian
  Triassic
  Jurassic
  Cretaceous
  Paleogene
  Neogene
  251
  299
  200
  145
  65
  23
  Now
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  Rhinoceroses
  Today there are only five or six species of rhinoceros, 
  all fairly similar. In prehistoric times the rhino family 
  was much more varied, its members ranging from 
  dog-sized animals to giants as tall as trees and heavier 
  than any other land mammals. Some prehistoric 
  rhinos were long-legged hornless animals built like 
  horses for speed; others were short and fat and 
  wallowed in water like hippos.
   
  ■ When  33–23 million years ago 
  (Late Paleogene–Early Neogene)
   
  ■ Fossil location  Pakistan, Kazakhstan, 
  India, Mongolia, China
   
  ■ Habitat  Plains
   
  ■ Length  26 ft (8 m)
   
  ■ Diet  Plants
  As big as a killer whale, this early hornless 
  rhinoceros was the largest land mammal of all 
  time. Its immense size and long neck allowed 
  it feed on treetops, as giraffes do today. Its 
  long, flexible lips could wrap around branches 
  and strip the leaves off.
  Paraceratherium
  PARRA-serra-THEER-ee-um
   
  ■ When  17–4 million years ago
   
  ■ Fossil location  USA
   
  ■ Habitat  Plains
   
  ■ Length  13 ft (4 m)
   
  ■ Diet  Grass
  Hundreds of 
  complete skeletons of Teleoceras were 
  found at Ashfall Fossil Beds in Nebraska 
  (see next page). The animals died after 
  choking on ash from a volcanic eruption 
  10 million years ago. Teleoceras was a large 
  rhinoceros with a small, conical horn on its 
  nose. But with its long, bulky body and 
  stumpy legs, it looked more like a hippo  
  than a rhino. Fossils have been found in 
  ancient river and pond deposits, suggesting  
  it wallowed in water a bit like a hippo, too.
  Teleoceras
  TEE-lee-oh-SEE-rass
  u STUMPY GRAZER
  Teleoceras had short stumpy legs 
  and a barrel-shaped body. Its tall 
  teeth were well suited to chewing 
  grass, and fossilized grass seeds 
  found in the throat of several 
  skeletons show that grass was its 
  main source of food.
   
  ■ When  3 million–10,000 years ago (Late Neogene)
   
  ■ Fossil location  Europe, Asia
   
  ■ Habitat  Plains
   
  ■ Length  12 ft (4 m)
   
  ■ Diet  Grass
  Also called the woolly rhino, Coelodonta had 
  a thick coat of long, shaggy hair that protected 
  it from the cold. It lived in Europe and Asia 
  during the last ice age, and we know what it looked 
  like thanks to frozen bodies found buried in icy 
  ground (permafrost) and prehistoric cave paintings 
  left by Stone Age people. About the size of a modern 
  white rhino, its body was massive, with short, stocky 
  limbs. On its snout was a pair of huge horns, each of  
  a different size—the front horn was as long as 3 ft  
  (1 m) in males. Coelodonta was a grazer, probably 
  grinding mouthfuls of grass and other plants after 
  tugging them out of the ground.
  Coelodonta
  SEE-low-DON-tah
  FAMILY FACT FILE
  Key features
   
  ■ Large size
   
  ■ Most had horns made from keratin 
  (the same material that nails are made of)
   
  ■ Large teeth for chewing leaves or grass
   
  ■ Feet with hooves
  When
  Rhinoceroses first appeared in the 
  Paleogene Period.
  MAMMALS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  255
   
  ■ When  2 million–126,000 years ago or later
   
  ■ Fossil location  Asia
   
  ■ Habitat  Plains
   
  ■ Length  20 ft (6 m)
   
  ■ Diet  Grass
  Elasmotherium was a large rhinoceros, 
  weighing about 3 tons, that lived until ice age 
  times and may have been hunted by early 
  people. Its huge, single horn has inspired 
  theories that this animal was the source of the 
  unicorn myth, although it probably vanished 
  too early in history to be remembered even  
  in folk tales. With legs longer than a modern 
  rhino’s, Elasmotherium may have been quicker 
  on its feet. Its teeth were large and flat-
  topped—adapted to a diet of grass and small 
  plants, which it perhaps tore from the ground 
  by swinging its head.
  Elasmotherium
  ell-AZZ-moe-THEER-ee-um
   
  ■ When  33–25 million years ago (Late Paleogene)
   
  ■ Fossil location  USA
   
  ■ Habitat  Plains
   
  ■ Length  9 ft (3 m)
   
  ■ Diet  Plants
  This cow-sized rhinoceros had no horns  
  and was not heavily armored like modern 
  rhinoceroses. Instead, Subhyrocodon relied on 
  its long, slender legs to flee from danger. Its 
  teeth had sharp crests, well-suited to mashing 
  leaves from trees and bushes.
  Subhyracodon
  sub-high-RACK-oh-don
  MAMMALS
  , THE LARGEST land 
  mammal of all time, 
  Paraceratherium weighed 
  about 16½ tons (15 metric 
  tons)—twice as much as 
  Tyrannosaurus and 
  four times heavier 
  than an elephant.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  256
  Ashfall fossil beds
  Twelve million years ago a volcano erupted in North America, 
  spreading a thick blanket of powdered glass (volcanic ash) and 
  killing many prehistoric animals. The animals lay undisturbed 
  until 1971. Welcome to the Ashfall Fossil Beds!
  A RARE FIND
  Hundreds of well-preserved mammal  
  skeletons were found at Ashfall Fossil Beds in 
  northeastern Nebraska, many complete, which 
  is incredibly rare. Some of the animals survived 
  the volcano’s ﬁrst eruption, but ash came to lie 
  about 1–2 ft (50 cm) deep, and gradually ﬁlled 
  their lungs as they attempted to graze. Ash is 
  made up of tiny shards of glass—the animals 
  didn’t stand a chance.
  MAMMALS
  Barrel-bodied rhinoceros 
  (Teleoceras)
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  257
  TAKE A LOOK
  Some of the ﬁnds have been 
  reconstructed to show how the 
  animals would have looked, 
  including this fossilized 
  skeleton of a baby barrel- 
  bodied rhinoceros (a Teleoceras). 
  Many skeletons have been left 
  in their original position.
  MAMMALS
  FACT FILE
   
  ■  Fossils of 17 different vertebrate 
  species, including 12 mammal species, 
  have been found at Ashfall Fossil Beds.
   
  ■ They include rhinos, horses, camels, 
  deer, dogs, and birds, all beautifully 
  preserved.
   
  ■ The site was discovered when a rhino 
  skull was seen poking out of a gully on 
  the edge of a cornfield.
   
  ■ The site is now a protected state park. 
  Special walkways allow visitors to walk 
  over the beds and watch paleontologists 
  at work in the summer.
  d THESE RHINOS were among 
  hundreds that died in agony after choking 
  on volcanic dust. So many perished that 
  the site has been called “rhino Pompeii.”
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  258
  Elephants and relatives
  The three living species of elephant are the largest land animals 
  today. But elephants weren’t always so huge. The earliest known 
  species was just 2 ft (60 cm) tall—the size of a cat. Over time 
  they grew larger and their trunks and tusks grew longer,  
  giving rise to an extraordinary range of giant mammals.
  Curved tusks 
  growing from 
  the lower jaw
  Large skull
   
  ■ When  10 million to 10,000 years ago (Neogene)
   
  ■ Fossil location  Europe, Africa, Asia
   
  ■ Habitat  Woodlands
   
  ■ Height  16 ft (5 m) tall at the shoulder
   
  ■ Diet  Plants
  The third largest land mammal that ever  
  lived, Deinotherium was slightly larger than 
  a modern African elephant. Its trunk was much 
  shorter than a modern elephant’s, and it had 
  backward-curving tusks that grew from the 
  lower jaw. It might have used the tusks to 
  dig up roots, strip bark, or pull down 
  branches to 
  reach the 
  leaves.
  Deinotherium
  DIE-no-THEER-ee-um
  FAMILY FACT FILE
  Key features
   
  ■ Almost all early elephants  
  had trunks
   
  ■ Mostly naked, wrinkled skin
   
  ■ Most had tusks
   
  ■ Columnlike legs
  When
  The first elephants appeared in the 
  Paleogene Period (about 40 million 
  years ago). 
  MAMMALS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  259
   
  ■ When  15–5 million years ago (Neogene)
   
  ■ Fossil location  N. America, Europe, Asia, Africa
   
  ■ Habitat  Swamps
   
  ■ Height  10 ft (3 m) tall at the shoulder
   
  ■ Diet  Plants
  Gomphotherium had two pairs of tusks—one 
  pair extending from its upper jaw, and another 
  smaller, shovel-shaped pair growing out of its 
  lower jaw. The larger tusks were probably used 
  for ﬁghting and display, and the smaller ones  
  to scrape up plants and strip tree bark.
  Gomphotherium
  GOM-foe-THEE-ree-um
   
  ■ When  10–6 million years ago (Neogene)
   
  ■ Fossil location  N. America, Africa, Asia, Europe
   
  ■ Habitat  Plains
   
  ■ Height  10 ft (3 m) tall at the shoulder
   
  ■ Diet  Plants
  Platybelodon
  PLAT-ee-BELL-oh-don
   
  ■ When  35–30 million years ago (Paleogene)
   
  ■ Fossil location  Africa
   
  ■ Habitat  Plains
   
  ■ Height  6 ft (2 m) tall at the shoulder
   
  ■ Diet  Plants
  Arsinoitherium belonged to an extinct family 
  of mammals that was related to the elephant 
  family, but it was not an elephant. It had no 
  trunk and looked like a rhino, with two huge 
  horns on its snout that were likely used by 
  males for display or ﬁghts over females. 
  Arsinoitherium’s hind legs were crooked 
  and perhaps better suited to a life wallowing 
  in water than walking  
  on land.
  Arsinoitherium
  AR-sin-oh-ee-THEER-ee-um
   
  ■ When  37–30 million years ago (Paleogene)
   
  ■ Fossil location  Egypt
   
  ■ Habitat  Swamps
   
  ■ Length  10 ft (3 m)
   
  ■ Diet  Plants
  Moeritherium
  MEH-ree-THEER-ee-um
  Short trunk
  Arsinoitherium’s 
  huge double horn 
  was hollow.
  The lower tusks of Platybelodon (“shovel 
  tusker”) were ﬂat and close together, forming  
  a shovel—perhaps used to scoop up plants 
  from water or marshes. Wear marks on the 
  lower tusks show that it also used its tusks  
  as blades to slice across branches. Like modern 
  elephants, Platybelodon had columnlike 
  legs supporting its body. It also had fatty  
  pads under its feet that helped to bear its 
  massive weight.
  MAMMALS
  Moeritherium was a close cousin of the 
  elephant family and had the beginnings of  
  a trunk. It was much smaller than modern 
  elephants and had a long body with very  
  short legs. It perhaps lived like a hippo, 
  wallowing in lakes and rivers and feeding  
  on water plants, using its ﬂexible lips to  
  grasp stems. The large teeth in both its  
  upper and lower jaws formed small tusks  
  that jutted out of its mouth.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  260
  MAMMALS
  Woolly mammoth
  Majestic mammoths once roamed in herds across the ice age 
  plains of North America, Europe, and Asia. Mammoths were 
  closely related to modern elephants—in fact, studies of frozen 
  mammoths found in Siberia show their DNA was almost 
  identical to that of living elephants. There were eight species  
  of mammoth, of which the most famous is 
  the woolly mammoth, which died 
  out only 3,700 years ago.
  Hair grew up to  
  3 ft (90 cm) long
  359
  416
  444
  488
  542 million years ago
  4.6 billion years ago
  Precambrian Eon
  Cambrian
  Ordovician
  Silurian
  Devonian
  Carboniferous
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  261
  MAMMALS
  When an Asian elephant is  
  born, its body is covered with  
  thick, brownish-red hair, similar to  
  the shaggy coat of its relative the 
  woolly mammoth. However, since  
  the Asian elephant lives in a warm, 
  tropical climate, it sheds its hair as  
  it grows older. Most adults have  
  only sparse hairy patches. African 
  elephants have even less hair. 
  LIVING RELATIVE
   
  ■ When  5 million–10,000 years ago (Neogene)
   
  ■ Fossil location  N. America, Europe, Asia, Africa
   
  ■ Habitat  Plains
   
  ■ Length  16 ft (5 m)
  Long, shaggy hair with fine wool underneath 
  covered the body of the woolly 
  mammoth. Most 
  adult woolly 
  Woolly mammoth
  WULL-ee MAMM-oth
  u BONE HUTS Prehistoric people built oval 
  or rounded huts from mammoth bones and tusks. 
  About 30 clusters of these huts have been found 
  in eastern Europe. 
  u SNOW SHOVEL Mammoths 
  may have used their tusks to scrape 
  away snow and ice when feeding. 
  Males probably also used their tusks 
  to impress females.
  mammoths were slightly bigger than African 
  elephants, but 6½ ft (2 m) tall “dwarf woolly 
  mammoths” have also been found on an  
  Arctic island. Adults had a distinct camel-like 
  hump on the shoulders and enormous, curved 
  tusks. Mammoths lived in Ice age 
  grasslands and had ridged teeth  
  for chewing tough grass and other 
  small plants. Studies of woolly 
  mammoth DNA reveal they were 
  more closely related to the Asian 
  elephant than the African species.
  Hind leg 
  shorter 
  than  
  front leg
  Tusk
  251
  299
  200
  145
  65
  23
  Now
  Permian
  Triassic
  Jurassic
  Cretaceous
  Paleogene
  Neogene
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  262
  . HIDDEN CLUES By studying 
  the place in which Lyuba was 
  found, the team concluded that her 
  body had been exposed for a year 
  before its discovery.
  u LYUBA was found in Russia’s 
  Arctic Yamal Peninsula, shown 
  by a dot on the map. 
  Scientists discovered a store of fat cells at the 
  back of Lyuba’s neck, which would have been 
  used to provide energy for keeping the baby 
  mammoth warm in its cold surroundings.
  Lyuba was so well preserved 
  that scientists even found 
  milk that she’d suckled from 
  her mother in her stomach. 
  Lyuba, the baby mammoth
  In 2007, a Siberian caribou-herder came across a 
  remarkably well preserved, frozen baby mammoth. 
  Lyuba (Lee-OO-bah), as the mammoth came to be 
  known (after the herder’s wife), is thought to have 
  died around 40,000 years ago. She is the best 
  specimen of a mammoth ever found.
  DID YOU KNOW?
   
  ■ Lyuba is small. She is just 4 ft long by 3 ft 
  wide (1.2 m x 90 cm).
   
  ■ Scientists believe Lyuba was about  
  30 days old when she died.
   
  ■ The mammoth may have died from 
  suffocation after being trapped in mud. 
   
  ■ Lyuba had “milk tusks”—small tusks that 
  fall out before the adult tusks grow.
  MAMMALS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  263
  . A REMOTE LOCATION A team of 
  scientists camped at the place Lyuba was found 
  a year after her discovery to gather more clues 
  about her life and death.
  TESTS, TESTS, TESTS
  Lyuba underwent numerous tests, ﬁrst at a medical 
  school in Japan, and then back in Russia. Her state of 
  preservation was amazing: scientists were able to look 
  closely at her skin, her eyes, her teeth, her organs, and 
  her eyelashes. Even some of her fur was still present. 
  Allowing her body to defrost slightly and for a short 
  time meant that tissue samples could be removed. 
  The scientists dealing with her wore protective 
  clothing to prevent contamination.
  LET’S INVESTIGATE!
  Following Lyuba’s discovery, an international team of scientists 
  set to work to build up a picture of what her life would have 
  been like. Scientists from Russia, France, Japan, and the United 
  States took samples and X-rays. They all concluded that Lyuba 
  was in healthy condition before she died and that her death was 
  the result of her accidentally slipping into mud.
  Scientists hope to 
  bring mammoths back 
  to life by using DNA 
  from frozen bodies.
  MAMMALS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  264
  Megatherium
  Also called the giant sloth, Megatherium was a close cousin of 
  modern tree sloths, but this prehistoric beast was as big as an 
  elephant and lived on the ground. Fossilized dung shows it 
  was a herbivore that ate dozens of diﬀerent kinds of plant. 
  It normally walked on all fours but could also rear up on 
  its hindlimbs to reach high branches, which it pulled 
  down with its claws. Megatherium vanished soon 
  after humans ﬁrst reached the Americas, 
  perhaps hunted to extinction.
  MAMMALS
  u MOST Megatherium fossils 
  have been found in the pampas, a 
  grassy area in South America. This 
  bone was among a ﬁnd of 12 animals 
  revealed when a drought caused a 
  river in Argentina to dry up.
  251
  299
  359
  416
  444
  488
  542 million years ago
  4.6 billion years ago
  Precambrian Eon
  Cambrian
  Ordovician
  Silurian
  Devonian
  Carboniferous
  Permian
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  265
   
  ■ When  5 million–10,000 years ago (Late Neogene)
   
  ■ Fossil location  S. America
   
  ■ Habitat  Woodlands
   
  ■ Length  20 ft (6 m)
   
  ■ Diet  Plants
  When Megatherium walked upright it was 
  almost twice the height of an elephant. It  
  was covered with thick, shaggy hair, under 
  which were bony plates that formed a kind  
  of armor. The teeth were blunt for mashing 
  leaves, but some experts think Megatherium 
  may have also used its 
  claws to scavenge  
  on dead meat  
  or even kill  
  for food.
  Megatherium
  meg-ah-THEER-ee-um
  u MEGATHERIUM’S hip bones were 
  especially strong. They supported the weight  
  of the huge body when the animal stood upright. 
  The stout tail also helped, acting as a prop.
  Modern sloths appear to be the laziest 
  animals on Earth, sleeping up to 18 hours  
  a day and moving with amazing slowness 
  when awake. Unlike Megatherium, today’s 
  sloths spend their lives hanging upside 
  down from trees. They cling to branches 
  with long arms and hooked claws, even 
  sleeping and eating  
  upside down.
  LIVING RELATIVE
  MAMMALS
  d MEGA CLAWS Megatherium 
  had enormous, curved claws that it  
  used to grasp branches and fight predators. 
  It could not place its feet flat on the 
  ground—instead, it walked on the sides  
  of its feet, with the claws turned inward. 
  Hip bone
  Three-toed 
  sloth, Panama
  200
  145
  65
  23
  Now
  Triassic
  Jurassic
  Cretaceous
  Paleogene
  Neogene
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  266
  MAMMALS
  Deer, giraffes, 
  and camels
  Around 20 million years ago, Earth’s forests began to 
  shrink as a new habitat—grassland—took over. This 
  change encouraged the spread of plant-eating hoofed 
  mammals, many of which had special stomachs 
  able to digest grass and other rough plant foods. 
  Such plant-eaters became very successful, and many 
  species evolved, including not only the deer, giraffes, 
  and camels on these pages but also sheep, goats, cattle, 
  buffalo, llamas, antelope, and hippos.
   
  ■  When  5 million–7,700 years ago 
  (Late Neogene)
   
  ■ Fossil location  Eurasia
   
  ■ Habitat  Plains
   
  ■ Length  10 ft (3 m)
   
  ■ Diet  Plants
  One of the largest deer ever known, 
  Megaloceros was about the size of 
  a modern moose. The male had  
  the most enormous antlers of all  
  time—from tip to tip, they measured 
  more than the total body length of  
  a tiger. It used its antlers for display  
  to attract females, as well as to scare off 
  rival males. Like other deer, it shed its  
  antlers every year. Megaloceros was hunted 
  by primitive humans, big cats, and wolves, 
  and died out 10,000 years ago.
  Megaloceros
  MEG-ah-LOSS-er-oss
  FAMILY FACT FILE
  Key features
   
  ■ After swallowing food, deer, giraffes, 
  and camels bring it up from the  
  stomach to chew a second time.
   
  ■ Three or four stomach chambers
   
  ■ Head often bears horns or antlers
   
  ■ Feet have even number of hoofed toes 
  (except camels, which don’t have hooves)
  When
  Even-toed hoofed mammals appeared 
  about 54 million years ago, became 
  widespread and common about  
  20 million years ago, and still exist. 
  Gigantic antlers
  Powerful back legs 
  for running quickly
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  267
  MAMMALS
   
  ■ When  16–5 million years ago (Neogene)
   
  ■ Fossil location  Asia, Europe, Africa
   
  ■ Habitat  Grasslands 
   
  ■ Length  51⁄4 ft (1.6 m) 
   
  ■ Diet  Plants
  Today, there are only two living members of  
  the giraﬀe family: the giraﬀe and the okapi.  
  In the past there were many more, including 
  Giraﬀokeryx. It had two pairs of pointed, 
  furry horns—one pair on its head and 
  another on its snout. At the back of its jaws 
  were ridged teeth, well suited to grinding 
  tough plants.
   
  ■ When  20–5 million years ago (Neogene)
   
  ■ Fossil location  N. America
   
  ■ Habitat  Woodlands
   
  ■ Length  3 ft (1 m)
   
  ■ Diet  Leaves
  A hoofed, cud-chewing mammal,  
  Cranioceras was a close relative 
  of early deer and giraﬀes. 
  Males had two short, 
  straight horns over their 
  eyes and a thick, blunt horn 
  that curved up at the back  
  of the head. Injuries on 
  fossilized horns suggest  
  they were used in ﬁghts  
  over mates or territories. 
  Giraﬀokeryx
  jee-RAFF-oh-CARE-icks
  Cranioceras
  CRAY-knee-OSS-eh-rass
   
  ■ When  25–16 million years ago 
  (Late Paleogene–Early Neogene)
   
  ■ Fossil location  USA
   
  ■ Habitat  Grasslands 
   
  ■ Size  2 ft (60 cm) tall
   
  ■ Diet  Grass
  Stenomylus was a small camel. Its neck, 
  legs, and body were delicate and slender, 
  more like those of a gazelle than a modern 
  camel. Unlike modern camels, Stenomylus 
  walked on tiptoe. It had huge molar teeth 
  with very deep roots. These must have 
  been used for chewing very tough or 
  gritty plants, as fossilized teeth show 
  signs of extreme wear during the life  
  of the animal.
  Stenomylus
  STEN-oh-MILE-us
   
  ■ When  15–5 million years ago (Neogene)
   
  ■ Fossil location  USA
   
  ■ Habitat  Woodlands and grasslands
   
  ■ Length  11 ft (3 m)
   
  ■ Diet  Plants
  Aepycamelus was a camel but looked a little 
  like a giraﬀe—it was very tall, with a long 
  neck. It could run fast on its long legs, each  
  of which had two hoofed toes with broad  
  pads underneath. Like all camels and giraﬀes, 
  it walked by swinging its left legs together  
  and then its right legs, a style of walking 
  known as “pacing.” It probably fed 
  on leaves more than grass.
  Aepycamelus
  AY-peeh-CAM-ell-us
  u LONG TONGUE 
  Giraﬀokeryx probably 
  had a long, ﬂexible 
  tongue to select the 
  tastiest leaves.
  Hoof
  Long neck
  Two-toed feet, ideal for 
  running at speed
  Long, slender neck
  d THE HORNS of 
  Cranioceras may have been 
  more like the fur-covered 
  horns of giraﬀes than the  
  bony antlers of deer.
  Slender 
  legs
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  268
  Aurochs
  The docile cattle seen on farms today  
  are descendants of a much wilder, fiercer, 
  and bigger ancestor: the aurochs. Now 
  extinct in the wild, the aurochs once 
  roamed in herds across Europe 
  and Asia. Stone Age people 
  hunted these fearsome animals 
  and made paintings of them in 
  caves, such as the one shown 
  on this page. Wild aurochs 
  survived in Europe until  
  1627, when the last animal  
  was killed in Poland.
   
  ■ When  2 million–500 years ago
   
  ■ Fossil location  Europe, Africa, Asia
   
  ■ Habitat  Forests
   
  ■ Length  9 ft (2.7 m)
   
  ■ Diet  Grass, fruit, and plants
  Much larger than a domestic cow,  
  the aurochs weighed about a ton and  
  had a very powerful, muscular neck and 
  shoulders, and huge, curved, forward-
  facing horns. Long feet and high ankles 
  made it a fast runner, and it could also 
  swim short distances. Males may have had 
  a black coat and females a reddish-brown 
  one. Both had a pale stripe along the spine. 
  Aurochs
  OR-ocks
  What the heck?
  In the 1920s, two German brothers, 
  Heinz and Lutz Heck, tried to breed 
  the aurochs back into existence. The 
  brothers found breeds of domestic 
  cow with aurochs-like qualities, such 
  as the large-horned highland cattle of 
  Scotland and the fierce fighting bulls 
  of Spain. By crossing the breeds, they 
  produced a new variety—heck 
  cattle—that looks like a small aurochs.
  Forward-facing 
  horns
  MAMMALS
  359
  416
  444
  488
  542 million years ago
  4.6 billion years ago
  Precambrian Eon
  Cambrian
  Ordovician
  Silurian
  Devonian
  Carboniferous
  Forward-facing 
  horns
  Aurochs 
  skeleton
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  269
  About 8,000 years ago, people in Iraq and 
  India learned how to tame aurochs and raise 
  them for milk, meat, and hides. Over time, 
  as breeders selected ever smaller and 
  calmer animals, the aurochs evolved into  
  the domestic cow. Although modern cattle 
  look very different from wild aurochs, they 
  belong to the same species.
  LIVING RELATIVE
  MAMMALS
  251
  299
  200
  145
  65
  23
  Now
  Permian
  Triassic
  Jurassic
  Cretaceous
  Paleogene
  Neogene
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  270
  Cave paintings
  In September 1940, four teenage boys set out to try 
  and ﬁnd a secret passageway rumored to exist near 
  their French village. What they discovered was a cave 
  system decorated with hundreds of paintings of 
  prehistoric animals. They’d found the 17,000-year-old 
  Lascaux cave paintings, now famous the world over.
  ICE AGE HERDS
  Lascaux was painted during the ice age, when northern 
  Europe was buried under sheets of ice but France was a 
  treeless, windswept tundra, crossed by huge herds of wild 
  animals. The people who painted the cave were hunters, 
  but, oddly, they didn’t paint their favorite prey—caribou.
  , ON THE RUN 
  Stags (left) and horses 
  are among the most 
  common animals in 
  Lascaux. Many 
  appear to be moving, 
  as though running in 
  herds. Such animals 
  migrated across the 
  tundra during the  
  last ice age, just as 
  caribou do today.
  Beautiful bison
  Cave painters used a mineral called red ocher to color 
  many of the animals. This picture shows a European 
  bison, a species that later disappeared from western 
  Europe but is now being reintroduced.
  u KILLER BIRDS This rock art in northern 
  Australia is thought to be more than 40,000 years 
  old. It shows two giant, flesh-eating, flightless birds 
  known as Genyornis. Nearby are paintings of 
  giant prehistoric kangaroos and Tasmanian tigers.
  MAMMALS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  271
  Predators
  Lascaux is just one of several painted 
  caves found in France and Spain. 
  Chauvet Cave in southern France 
  contains paintings up to 30,000 
  years old and features predators such 
  as lions, hyenas, panthers, and bears, 
  as well as mammoths and rhinos. 
  u LIONS were among the animals painted at Chauvet 
  Cave in France. Now found only in Africa and Asia, lions 
  lived throughout Europe in prehistoric times.
  u HAND ART Prehistoric artists 
  created handprints by placing a 
  hand on the cave wall and spitting 
  red ocher all over it.
  MAMMALS
  . LASCAUX ANIMALS 
  The Lascaux animals include 
  prehistoric species that no longer 
  exist, such as mammoths and the 
  aurochs (the wild ancestor of the 
  domestic cow, shown below with 
  huge horns). There are also lions, 
  bison, hundreds of horses, stags, 
  one bear, and one rhino. 
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  Andrewsarchus
  When people mention “hoofed mammals,” we normally think  
  of plant-eaters like deer and sheep. But, millions of years ago, 
  some hoofed mammals were bloodthirsty carnivores. The most 
  terrifying of all was probably Andrewsarchus, a gigantic predator 
  that prowled the plains of Mongolia. Only one good fossil of 
  Andrewsarchus has been found: an enormous skull measuring 
  33 in (83 cm) in length. Though scientists can’t be sure, the huge 
  skull suggests the animal may have been twice as big as a grizzly 
  bear, making it the largest carnivorous land mammal of all time.
   
  ■ When  45–35 million years ago (Paleogene) 
   
  ■ Fossil location  Mongolia 
   
  ■ Habitat  Plains of Central Asia 
   
  ■ Length  13 ft (4 m)  
   
  ■ Diet  Meat
  Andrewsarchus may have 
  looked like a giant wolf or bear.  
  It had a long snout and immensely 
  powerful jaws, with long, pointed canine 
  teeth at the front for piercing flesh, and 
  blunter teeth at the rear that may have 
  been used to crush bones. Like a bear,  
  it may also have eaten plant foods and 
  scavenged from carcasses—its sheer  
  size would have been enough to scare 
  other predators away from their kills. 
  Some scientists think Andrewsarchus is 
  a close relative of whales, since they share 
  a similar jaw structure. 
  Andrewsarchus
  ANN-droo-SAR-kuss
  MAMMALS
  359
  416
  444
  488
  542 million years ago
  4.6 billion years ago
  Precambrian Eon
  Cambrian
  Ordovician
  Silurian
  Devonian
  Carboniferous
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  MAMMALS
  DID YOU KNOW...?
  Andrewsarchus is named after Roy Chapman 
  Andrews (1884–1960), an American explorer 
  and fossil hunter. Andrews led many 
  expeditions to the Gobi Desert in Mongolia 
  in the 1920s, where he discovered the 
  dinosaurs Velociraptor and Protoceratops 
  and the ﬁrst known dinosaur eggs (see 
  pages 192–193). In 1923, he found a partial 
  skull of Andrewsarchus—the only fossil, 
  along with a few bones, that has been 
  found. This priceless fossil is now on 
  display at the American Museum of 
  Natural History, in New York City. 
  251
  299
  200
  145
  65
  23
  Now
  Permian
  Triassic
  Jurassic
  Cretaceous
  Paleogene
  Neogene
  Roy Chapman 
  Andrews with 
  dinosaur eggs in 
  the Gobi Desert
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  274
  MAMMALS
  All land animals evolved from sea-dwelling ancestors that left the water 
  and adapted to life on land. Whales are one of several groups of 
  animals that then did the reverse and went back to the sea. They 
  evolved from hoofed land mammals and are distantly related to cows 
  and pigs, while their closest living land relative is the hippopotamus!
  Whales in the making
  THE WALKING WHALE
  Ambulocetus, an early member of the whale family, lived more 
  than 50 million years ago. A bit like an otter, it was equally  
  at home on land and in water. Its front feet had small hooves 
  for walking on land, while its back feet served to propel it 
  through the water. Its name means “walking whale.”
  CLOSE COUSINS
  The theory that whales are related to 
  hippopotamuses was ﬁrst suggested  
  in 1870, but most scientists dismissed  
  it as unlikely. More recently, careful 
  comparison of whale DNA and hippo 
  DNA has shown that hippos probably 
  are the closest living relatives of whales.
  . HIPPOS spend much of their lives in 
  water but are less aquatic than whales.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  275
  THE FAMILY TREE
  Scientists haven’t found enough fossils to trace the evolution of whales in 
  full. However, a handful of fascinating discoveries from diﬀerent parts of 
  the whale family tree give us snapshots of evolution in action, with later 
  species ever-better adapted to life in water as their limbs evolved into 
  ﬂippers and their nostrils moved backward to become blowholes.
  MAMMALS
  WHALES TODAY
  There are now more than 100 
  species of whale and dolphin. 
  They are divided into two main 
  types: toothed whales, which 
  hunt ﬁsh, and baleen whales, 
  which use plates of bristles in the 
  mouth to sift small animals from 
  the water. The humpback whale 
  (right) is a type of baleen whale.
  , PAKICETUS 
  is the oldest known member 
  of the whale family (the 
  order Cetacea). It lived on 
  land 52 million years ago.
  u EVENTOED 
  HOOFED MAMMALS 
  Whales are close relatives of 
  even-toed hoofed mammals. 
  , AMBULOCETUS was a predator that 
  was equally comfortable on land or in water.
  , RODHOCETUS had large, 
  paddling feet for swimming, but 
  its ear bones were very whalelike. 
  , BASILOSAURUS was 
  like a sea monster. Its front 
  limbs had become ﬂippers; 
  its hind limbs were tiny, 
  useless stumps.
  , DORUDON was shaped 
  like a whale but had hind 
  ﬂippers, and its nostrils were 
  midway between the snout 
  and the top of the head.
  u Modern baleen 
  whales form the  
  family Mysticeti.
  , Modern toothed whales 
  form the family Odontoceti.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  276
  MAMMALS
  Primates
  The primates are a family of mostly 
  tree-dwelling animals that includes 
  monkeys, apes, and ourselves. The  
  ﬁrst primates were small, squirrel-like 
  animals that scampered around in the 
  trees about the same time that the dinosaurs died 
  out. Once the dinosaurs were gone, primates 
  evolved into many new species, becoming larger 
  and more intelligent over time.
   
  ■ When  47 million years ago (Paleogene) 
   
  ■ Fossil location  Germany 
   
  ■ Habitat  Woodlands of western Europe 
   
  ■ Length  2 ft (0.6 m)
   
  ■ Diet  Fruit and plants
  Only one fossil of Darwinius has been 
  found: a skeleton, nicknamed “Ida,” so 
  beautifully preserved that soft fur can 
  be seen all over the body (left). Even 
  Ida’s last meal of leaves and fruit was 
  preserved in her stomach. Darwinius 
  looked like a lemur. An agile climber, 
  it had “opposable thumbs,” which 
  means that its thumbs moved the 
  opposite way to the ﬁngers, allowing  
  it to grasp branches and handle food.
  Darwinius
  dar-WIN-ee-us
  FAMILY FACT FILE
  Key features
   
  ■ Large brains
   
  ■ Most had forward-facing eyes
   
  ■ Grasping hands and feet
   
  ■ Most had nails, not claws
  When
  The earliest primates appeared about 
  65 million years ago. Numerous 
  species of primate still exist today.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  277
   
  ■ When  65–60 million years ago (Paleogene) 
   
  ■ Fossil location  N. America, Europe, and Asia 
   
  ■  Habitat  Woodlands of N. America, 
  Europe, and Asia 
   
  ■ Length  2 ft (0.6 m)
   
  ■ Diet  Plants
  The oldest known primate is Plesiadapis, 
  which looked more like a squirrel than a 
  monkey. It had a bushy tail, a long snout, 
  ratlike incisor teeth for gnawing, and eyes on 
   
  ■  When  9 million–250,000 
  years ago (Neogene) 
   
  ■ Fossil location China, India, and Vietnam 
   
  ■ Habitat  Woodlands of Asia 
   
  ■ Length  9 ft (2.7 m)
   
  ■ Diet  Plants
  Twice the size of a gorilla, Gigantopithecus was 
  the largest ape that ever lived—the King Kong 
  of its day. Some scientists think it may be the 
  source of the Yeti myth. 
  Only teeth and jaws 
  have been found.  
  The pattern of  
  wear suggests  
  it fed on 
  bamboo. 
  Gigantopithecus
  gi-GAN-toe-PITH-eck-uss
  Eosimias
  EE-oh-SIM-ee-uss
   
  ■ When  15–10 million years ago (Neogene) 
   
  ■ Fossil location  Africa, Europe, and Asia 
   
  ■  Habitat  Woodlands of Europe, 
  Asia, and Africa 
   
  ■ Length  2 ft (0.6 m)
   
  ■ Diet  Plants
  Dryopithecus
  DRY-oh-PITH-eck-uss
   
  ■ When  45–40 million years ago (Paleogene) 
   
  ■ Fossil location  China 
   
  ■ Habitat  Woodlands 
       of Asia 
   
  ■ Length  2 in 
       (5 cm)  
   
  ■  Diet  Insects 
  and plants
  Eosimias was one of 
  the earliest primates. 
  Unlike the enormous 
  mammals that 
  evolved after the  
  age of dinosaurs, Eosimias 
  was like a tiny fur ball and would have  
  easily fit into the palm of a child’s hand.  
  Its large eyes may have helped it to spot 
  predators easily, especially at night. It  
  probably fed on nectar and insects. 
  Plesiadapis
  PLEEZ-ee-ah-DAP-iss
   
  ■ When  12–7 million years ago (Neogene) 
   
  ■ Fossil location  Nepal, Pakistan, Turkey 
   
  ■  Habitat  Woodlands of Central Asia 
   
  ■ Length  5 ft (1.5 m)
   
  ■ Diet  Plants
  Sivapithecus
  SEE-vah-PITH-eck-uss
  MAMMALS
  Orangutans are the largest tree-dwelling 
  mammals today. There are two species: the 
  Bornean orangutan and the Sumatran 
  orangutan. Both are highly intelligent, able 
  to make and use 
  simple tools. 
  Both are also 
  endangered, 
  due to loss  
  of their 
  rainforest 
  habitat.
  LIVING RELATIVE
  Lower jaw  
  fossil
  u LONG ARMS
  Dryopithecus used 
  long arms to swing 
  under branches like  
  a gibbon.
  Sivapithecus had the build of a chimpanzee, 
  but its face was more like that of an orangutan, 
  to which it was closely related. It lived in 
  woodland, but scientists think it may have 
  spent much of its time on the ground. It had 
  large molar teeth (rear teeth), suggesting its 
  diet included a lot of tough food such as  
  grass seed gathered on the ground, although  
  it probably also climbed trees for fruit and 
  may have slept in trees at night.
  This primate was about  
  the size of a chimpanzee and 
  spent most of its life up  
  in the trees. It had very 
  long, strong arms, which 
  it used for swinging 
  from branch to branch. 
  Like a chimp, it could 
  also walk on all fours, 
  but rather than walking on 
  the knuckles of its hands as 
  chimps do, it walked with 
  its palms flat on the 
  ground. It had a large 
  brain, but was only a 
  distant relative of 
  human beings. 
  the sides of its head for spotting predators. 
  However, the rear teeth of Plesiadapis were flat 
  like those of living primates, suggesting its diet 
  included fruit and other soft plant foods.
  Large 
  canine 
  tooth
  This partial skull 
  was rebuilt from 
  broken pieces.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  278
  Australopithecus
  Today, all ape species (except for humans) live in 
  forests, but four million years ago things were 
  different. Africa was home to a range of 
  apes that lived on open ground and 
  walked upright as we do. The best 
  known of these walking apes, 
  Australopithecus, is probably 
  our own ancestor.
   
  ■ When  4–2 million years ago (Neogene)
   
  ■ Fossil location  Africa
   
  ■ Habitat  Open woodland, grassland
   
  ■ Height  4–4½ ft (1.2–1.4 m)
   
  ■ Diet  Fruit, seeds, roots, insects, small animals
  In many ways, Australopithecus was like its 
  very close relative the chimpanzee. It had a 
  small, hair-covered body, powerful arms for 
  climbing, and a brain one-third the size of 
  ours. However, its hip bones and feet were  
  like those of modern humans, indicating that 
  Australopithecus could walk upright, although 
  less nimbly than we can. Some scientists think 
  Australopithecus lived in social groups like 
  those of gorillas, ruled by a single male that 
  was much larger than the females.
  Australopithecus
  OSS-tra-low-PITH-ee-cuss
  MAMMALS
  u HANDS FREE Walking on only two 
  feet left the arms free for other jobs, such as 
  carrying. This was to be very important later 
  in human evolution, when our ancestors 
  made tools such as hunting weapons.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  Footprints from the past
  In 1976, scientists found what looked like 
  fossilized human footprints in Tanzania, 
  Africa—but the prints turned out to be 
  3.6 million years old. They were left by a 
  group of three Australopithecus walking 
  over volcanic ash and clearly show that 
  these animals could walk on two feet.
  SMALL BRAIN
  Scientists once thought our ancestors evolved large brains before 
  they mastered the tricky business of walking. But Australopithecus 
  proves the opposite was true—it could walk, but its brain was 
  barely larger than a chimp’s. This animal didn’t have the 
  brainpower needed for language and couldn’t talk, although 
  individuals may have whooped and screeched to communicate.
  LANDSCAPE AND FOOD
  Today, most apes live in jungles, but 
  Australopithecus lived in a more open 
  landscape—a mixture of grassy areas and patches 
  of trees. Its large jaws and thickly enameled 
  molars (back teeth) show it foraged for tough, 
  plant foods like roots and seeds, but like other 
  apes it probably had a very varied diet that 
  included fruit, insects, and perhaps meat.
  Sloping forehead
  Powerful 
  jaws and 
  large teeth
  u THIS RECONSTRUCTION, based on a skull of Australopithecus, 
  shows how apelike it looked. Its small braincase gave it a flat, sloping 
  forehead quite unlike the upright forehead of modern humans.
  The chimpanzee is a very close relative of 
  Australopithecus. Chimpanzees sometimes use 
  rocks and sticks as simple tools. They use rocks 
  to crack nuts and sticks to ﬁsh termites out of 
  their nests. It’s likely that Australopithecus also 
  used simple tools like these, but there’s little 
  fossil evidence that it could make the kinds  
  of stone tools that the later humans made.
  LIVING RELATIVE
  MAMMALS
  In 1975, scientists found fossilized  
  remains of at least 13 Australopithecus 
  bodies at the same site in Ethiopia. The 
  find was nicknamed “the first family,”  
  although they may have been unrelated  
  victims of predators such as lions.
  Braincase
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  280
  Homo erectus
   
  ■ When  2–0.1 million years ago (Neogene) 
   
  ■ Fossil location  Africa, Europe, Asia 
   
  ■ Habitat  Woodland and grassland 
   
  ■ Height  6 ft (1.8 m) 
   
  ■ Diet  Plant foods and meat 
  Homo erectus was very similar in size and 
  shape to a modern human, with a tall, 
  athletic body and long legs. The slender 
  build suggests it lived in a hot climate 
  and could sweat to lose heat, which in 
  turn means it was probably hairless. It 
  had a smaller brain than ours, and a 
  ﬂatter forehead and larger jaws and teeth 
  made its face very diﬀerent, too.
  Homo erectus
  HOE-moe eh-RECK-tuss
  Over millions of years, as Australopithecus (see previous 
  page) became ever better adapted to life on the ground, 
  it changed and evolved, giving rise to new species that 
  looked much more human. One of the best known is 
  Homo erectus—a tall, hairless creature that appeared 
  about two million years ago. Homo erectus knew how 
  to make stone tools and perhaps even ﬁres. It spread 
  beyond Africa, reaching deep into Europe and Asia.
  MAMMALS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  281
  Long, low 
  skull
  Thick ridge of bone 
  across brow
  Large jaws 
  and teeth
  3
  4
  1
  2
  DID YOU KNOW...?
  In 1891, Eugene Dubois, a Dutch scientist, found 
  the ﬁrst known Homo erectus fossil on the island 
  of Java in Indonesia. Dubois thought that humans 
  evolved from apes in Asia rather than Africa, but 
  later discoveries of Australopithecus fossils 
  in Africa proved him wrong. 
  Multipurpose tool
  Homo erectus’s favourite tool was something called a hand axe. It was made 
  by chipping flakes off a stone (using a heavier rock as a hammer) to make 
  sharp edges on the sides. It was used for all sorts of jobs, from skinning and 
  butchering animals to smashing bones (to release the marrow), and digging 
  for deep roots. Such tools made it much easier for Homo erectus to eat meat.
  Making fire
  Could Homo erectus make fire? Scientists don’t 
  know for sure. Patches of ash in caves inhabited  
  by Homo erectus 400,000 years ago hint that the 
  species could create fire, but the ash might be from 
  wild fires. The mastery of fire was an important step 
  in human history. It allowed our ancestors to cook, 
  making food safer to eat and easier to digest. Fire 
  can also be used to scare predators away, and it 
  provided vital warmth as early humans spread  
  to cold parts of the world.
  Brain size
  Fossilized skulls reveal that 
  Homo erectus’s brain was at 
  least twice the size of that  
  of Australopithecus, though 
  only 70 per cent as big as  
  a modern human’s. Some 
  scientists think the larger 
  brain allowed Homo erectus 
  to use language and to live 
  in complex social groups.
  Hand axe
  Sharp edge
  MAMMALS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  Neanderthals
  During the ice age, Europe was inhabited by a race 
  of physically powerful and intelligent people known 
  as Neanderthals. The Neanderthals had large brains, 
  language, clothing, shelters, fire, tools, and maybe 
  even art—but they were not the same species as us. 
  When our own species finally spread from Africa to 
  Europe 40,000 years ago, the Neanderthals vanished.
   
  ■ When  350,000–30,000 years ago (Neogene) 
   
  ■ Fossil location  Europe and Asia 
   
  ■ Habitat  Ice age grasslands and woodlands
   
  ■ Height  5 ft 5 in (1.66 m)
   
  ■ Diet  Mainly meat
  Neanderthals were shorter, stockier, and far stronger 
  than us. Their compact build helped them cope  
  with the cold environment, and their great strength 
  was needed for hunting wild animals as big as 
  mammoths, although they probably scavenged for 
  meat, too. Their brains were at least as big as ours, 
  but their heads were flatter in shape, with a lower, 
  more sloping forehead, a heavy ridge of bone over the 
  eyes, a huge nose, and large jaws that jutted forward.
  MAMMALS
  Homo neanderthalensis
  HOE-moe nee-AN-der-thaw-LEN-siss
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  283
  Central heating
  To survive the freezing cold of the Ice age, 
  the Neanderthals used fire to keep their 
  homes warm. They wore clothes made  
  of animal skin and fur, much like Arctic 
  people do today. They may even have 
  lined their beds with rabbit fur to  
  keep themselves snug at night. 
  Six feet under
  Neanderthal skeletons have been found in what appear  
  to be graves, suggesting that Neanderthals deliberately 
  buried their dead. Unlike later humans, however, they 
  seldom placed sacred or precious objects with the bodies.
  Tool kit 
  Like Homo erectus, the Neanderthals 
  made stone tools by chipping flakes off  
  a rock to form a sharp edge. Their tools 
  were much more varied than those of 
  Homo erectus and included heavy-duty 
  hand axes; smaller, more delicate knives; 
  and spearheads. Neanderthals probably 
  also made tools from wood that  
  have not survived.
  Clues from bones
  Scientists have found 
   the remains of around 275 
  Neanderthals. Wear marks and 
  injuries on the bones reveal that their 
  owners endured great physical stress and 
  often violence. The injuries match those 
   of rodeo riders—perhaps Neanderthals 
  wrestled with the animals they hunted. 
  Some Neanderthal bones bear scratches 
  made by stone tools. Some experts think 
  this means Neanderthals were cannibals. 
  Others think the dead were “defleshed” 
   in religious ceremonies before burial.
  The Neanderthal voicebox  
  was just like ours, which 
  means Neanderthals could 
  probably speak.
  Stone knife
  Large skull 
  housed a 
  bigger brain
  Hand ax with two 
  blades and point
  Hand ax with 
  rounded blade
  MAMMALS
  Blade
  Handle
  Handle
  Blade
  Handle
  A heavy brow ridge 
  gave Neanderthals a 
  glowering expression.
  Numerous chips and 
  scratches suggest the 
  teeth were used as tools.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  284
  MAMMALS
  Myths and legends
  Dinosaurs in the Congo? Abominable snowmen in the 
  mountains? Ever since people began telling stories, there 
  have been tales of fantastic animals. While many are just 
  tall tales about mythical beasts that never existed,  
  some might just have a grain of truth in them— 
  they may be ancient stories from a time when  
  long-lost prehistoric animals still lived.
  Half human, half ape
  From Sasquatch (Bigfoot) in North America to the Yeti  
  in the Himalayas and Orang Pendek in Sumatra, tales of 
  mysterious ape-men are common around the world. Some 
  scientists believe the origin of these old stories might lie in 
  the distant past, when humans spread from Africa to other 
  parts of the world and came across our living “hominin”  
  relatives, including Neanderthals and Homo erectus.
  WHAT’S THAT?
  The ﬁrst dinosaur was not correctly identiﬁed 
  until the 1800s—until then, people had no 
  idea what fossils were. A famous description 
  and picture of what was later identiﬁed as a 
  dinosaur bone was published in 1677 by the 
  English naturalist Robert Plot. He claimed it 
  was part of the thigh bone of a human giant.
  Robert Plot thought this fossil 
  was the knee-end of a giant 
  human’s thigh bone.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  285
  Caveman versus dinosaur
  In old movies such as 1966’s One 
  Million Years B.C., cavemen are 
  shown battling with dinosaurs. This  
  is impossible—dinosaurs vanished at 
  least 63 million years before cavemen 
  existed. And dinosaurs didn’t stand 
  with their tails on the ground, as  
  old movies, toys, books, and pictures 
  often show them.
  A living dinosaur?
  The mokèlé-mbèmbé is a 
  legendary creature likened 
  to a sauropod dinosaur and 
  said to live in the Congo 
  River basin. In some ways it 
  is similar to the Loch Ness 
  monster (see page 102).
  Serpents’ heads
  Ammonite fossils are the source of 
  many legends. According to English 
  folklore, they are serpents that have 
  been turned to stone—hence their 
  old name, “snakestones.” Sometimes 
  the head of a serpent was carved on 
  an ammonite fossil.
  The elephant bird
  Sinbad the Sailor was a ﬁctional Arab sailor 
  whose adventures took him to magical lands. 
  In one story he is carried away in the claws of a 
  gigantic bird. This tale may have been inspired 
  by the elephant bird of Madagascar, a giant 
  ﬂightless bird that lived until the 1600s and 
  was probably known to Arab sailors.
  The gigantic eggs of 
  elephant birds can 
  still be found in 
  Madagascar.
  MAMMALS
  A horned horse?
  Some people think the legend 
  of the unicorn might be based 
  on ancient folk tales about the 
  extinct rhino Elasmotherium 
  (see page 255), which had an 
  enormous single horn. 
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  286
  Modern humans
  Fossil evidence and studies of our genes show that our 
  own species—Homo sapiens—evolved in Africa some 
  200,000 years ago. Around 60,000 years ago, modern 
  humans spread from Africa to new continents, taking 
  with them tools, art, and a way of life more advanced 
  than anything seen before. As our species spread, other 
  more primitive humans and many large mammal 
  species vanished—perhaps victims of our success.
   
  ■ When  200,000 years ago to now (Neogene)
   
  ■ Fossil location  Worldwide, except for Antarctica and some 
  remote islands
   
  ■ Habitat  Nearly all land habitats
   
  ■ Height  6 ft (1.8 m)
  Compared to other apes and primitive humans, Homo 
  sapiens has a small, flat face; a high forehead; a huge, 
  balloon-shaped braincase; small brow ridges; and a 
  prominent chin. Most importantly, our species has  
  a large and complex brain. Intelligence allowed our 
  ancestors to devise ingenious new hunting tools,  
  build shelters, make clothes, and harness fire. Language 
  allowed them to pool knowledge and share skills. Early 
  Homo sapiens lived in complex societies in which 
  people looked after their sick and left offerings in 
  graves—a sign they believed in an afterlife.
  Homo sapiens
  HOE-moe SAP-ee-enz
  u BURIAL ORNAMENTS 
  This 24,000-year-old skeleton  
  of a young man was found in a 
  cave in Italy, adorned with a hat 
  and a necklace made of shells.
  MAMMALS
  Early ape
  Australopithecus
  Homo erectus
  Homo sapiens
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  287
  Harpoons
  Needle
  Spear points
  Carved tools
  Early Homo sapiens was a much 
  more skillful toolmaker than other 
  hominins (human relatives). As early  
  as 73,000 years ago, humans in southern 
  Africa were carving finely made tools from 
  bone and making jewelry from shells. By 
  18,000 years ago, humans in Europe were 
  using bone, ivory, and caribou antlers to make 
  spear throwers, harpoons, and even needles. 
  Many of these were engraved with artistic 
  designs, such as animal heads.
  u THE BUSHMEN of southern Africa 
  follow a way of life known as hunter-gathering. 
  Instead of keeping livestock for food or growing 
  crops, their gather all their food from the wild. 
  All early Homo sapiens were hunter-gatherers, 
  too. This way of life did not begin to die out 
  until farming began about 8,000 years ago.
  MAMMALS
  Spear thrower
  Bone and  
  antler tools from 
  ice age Europe
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  288
  MAMMALS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  289
  MAMMALS
  BUSHMAN ROCK ART
  The rock art of the native people of southern Africa 
  (Bushmen) was made in the same way as the ancient 
  cave paintings of ice-age France (see page 270), but 
  Bushman rock art is only a few hundred years old.  
  It shows magical ceremonies such as dances in which 
  healers are at work.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  290
  Adaptation  A feature of an animal that 
  evolved in response to its environment  
  or way or life. The long neck of a giraffe,  
  for instance, is an adaptation that helps  
  it reach treetops.
  Algae  Primitive plants and plant-like 
  organisms that grow in wet conditions. 
  Amber  The fossil form of a sticky resin 
  made by certain trees. Perfectly preserved 
  insects and other organisms have been  
  found in amber.
  Ammonites  Prehistoric sea creatures with 
  coiled, chambered shells. Ammonites were 
  relatives of octopuses and squids.
  Amphibian  A type of cold-blooded 
  vertebrate, such as frog or newt. Most 
  amphibians develop from larvae that live in 
  water and breathe through gills, becoming 
  land-dwelling adults that breathe air  
  through lungs.
  Ancestor  An animal or plant species from 
  which a more recent species has evolved.
  Angiosperms  A scientific term for flowering 
  plants. This group includes broad-leaved trees 
  and grasses. 
  Ankylosaurs  Four-legged, armoured, 
  plant-eating dinosaurs with bony plates  
  that covered the neck, shoulders, and back. 
  Archosaurs  A major group of reptiles that 
  originated in the Triassic Period. It includes 
  dinosaurs, pterosaurs, and crocodylomorphs.
  Arthropods  Invertebrates with segmented 
  bodies and a hard outer covering 
  (exoskeleton). Extinct arthropods include 
  trilobites and eurypterids. Living ones  
  include insects and spiders.
  Aurochs  An extinct variety of wild cattle that 
  was the ancestor of modern cattle.  
  Australopithecus  A prehistoric member 
  of the human family that may be a direct 
  ancestor of modern humans. Australopithecus 
  looked like a chimpanzee but walked upright 
  like a human.
  Bivalves  Aquatic animals such as clams and 
  oysters that live in a hinged shell. The two 
  halves of the shell are usually mirror images  
  of each other. 
  Bony fish (Osteichthyans)  Fish with a 
  skeleton made of bone. Some fish, such as 
  sharks, have a skeleton made of cartilage 
  rather than bone and are classed as 
  cartilaginous fish.
  Burgess Shale Formation  A site in British 
  Columbia, Canada, where many important 
  Cambrian fossils were discovered. Among the 
  130 species identified are sponges, jellyfish, 
  worms, and arthropods.
  Cambrian  The first period of the Palaeozoic 
  Era, from 542 to 488 million years ago. This 
  was when most of the main invertebrate 
  groups appeared in the fossil record. 
  Camouflage  Colours or patterns on an 
  animal’s skin or fur that help it to blend with 
  its surroundings and hide.
  Carboniferous  The fifth period of the 
  Palaeozoic Era, from 359 to 299 million  
  years ago. During this period, forests  
  covered the land and were inhabited by 
  insects and four-legged vertebrates  
  (tetrapods), including the first amphibians 
  and the first reptiles. 
  Carnivore  An animal that eats meat. The 
  term carnivore can also refer to a specific 
  family of mammals (the order Carnivora).
  Cartilage  A firm, rubber-like tissue that 
  is part of the skeleton of vertebrates. In  
  fish such as sharks, the entire skeleton is  
  made of cartilage.
  Cephalopod  Sea creatures with big eyes 
  and a well-developed head surrounded by a 
  ring of tentacles. Examples include octopuses, 
  squid, cuttlefish, and ammonites.
  Ceratopsians  Two-legged and four-legged, 
  plant-eating dinosaurs with a deep beak and  
  a bony frill at the rear of the skull. They 
  include the horned dinosaurs.
  Chelicerate  A type of invertebrate with 
  special mouthparts called chelicerae that are 
  used as pincers or fangs. Modern examples 
  include spiders and scorpions.
  Cold-blooded  An animal is described as 
  cold-blooded if its body temperature rises  
  and falls  along with the outside temperature. 
  Animals that maintain a constant body 
  temperature are described as warm-blooded.
  Cretaceous  The last period of the Mesozoic 
  Era, from 145 to 65 million years ago.
  Crinoids (sea lilies)  Plant-shaped sea 
  creatures with feathery arms that live 
  anchored to the sea floor by long stalks.  
  They are related to starfish and sea urchins.
  Crocodylomorphs  A group of reptiles that 
  includes crocodiles, alligators, and their many 
  extinct relatives. Crocodylomorphs appeared 
  at about the same time as the dinosaurs and 
  were once much more varied than today. 
  Crustaceans  A large and varied group 
  of arthropods, most of which live in  
  water. Living examples include crabs,  
  shrimps, and woodlice.
  Cycads  Palm-like, seed-bearing plants 
  that are topped by a crown of fern-like  
  leaves. They may be short and shrub-like,  
  or grow as high as 20 m (65 ft).
  Descendant  An animal or plant species that 
  evolved from an early species (its ancestor). 
  Devonian period  The fourth period of the 
  Palaeozoic Era, from 416 to 350 million years 
  ago. The Devonian is also called the “age of 
  fish”. During this period, tetrapods (four-
  legged vertebrates) evolved from fish.
  Digit  A finger, thumb, or toe.
  Glossary
  GLOSSARY
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  291
  Dinosaurs  A large group of archosaurs with 
  upright limbs. Dinosaurs were the dominant 
  land animals for 160 million years.
  DNA  Deoxyribonucleic acid, a chemical 
  whose molecules carry genetic instructions 
  from one generation to the next in nearly  
  all organisms. (See Genes.) The complex 
  double-helix structure of DNA was  
  discovered in the 1950s.
  Domesticated  Bred to be tame. Cows, sheep, 
  and dogs are examples of domestic animals. 
  Dromaeosaurs  A group of bird-like, two-
  legged, carnivorous dinosaurs. Most grew  
  no longer than 2 m (6 ft). Dromaeosaurs 
  lived in all northern continents. 
  Echinoderms  Marine invertebrates with a 
  hard, chalky skeleton and a five-rayed 
  symmetry. They evolved during the Cambrian 
  Period and include starfish, sea lilies, sea 
  cucumbers, and sea urchins.
  Ediacaran biota  Fossil organisms named 
  after those found in the Ediacaran Hills of 
  Australia. The sea-dwelling, soft-bodied 
  organisms lived about 550 million years  
  ago and were some of the earliest animals.
  Embryo  An animal or plant in an early 
  stage of development from an egg or a seed.
  Environment  The natural surroundings 
  in which an animal or plant lives.
  Era  A very long unit of time. Eras are 
  divided into shorter units called periods. The 
  Mesozoic  Era, for example, is divided into 
  the Triassic, Jurassic, and Cretaceous periods.
  Eurypterids (sea scorpions)  An extinct 
  group of large arthropods related to modern 
  scorpions. Eurypterids lived in the sea and 
  freshwater habitats during the Palaeozoic Era. 
  Some grew more than 2 m (6 ft 6 in) long. 
  Evolution  The gradual change of animal 
  or plant species over long periods of time. 
  Evolution is driven mainly by a process  
  called natural selection.
  Excavation  Digging out and removing 
  fossils or other objects from the ground.
  Exoskeleton  An external skeleton. Animals 
  such as crabs have an exoskeleton. In contract, 
  humans have an internal skeleton.
  Extinction  The dying-out of a plant 
  or animal species. Extinction can happen 
  naturally as a result of competition between 
  species, changes in the environment,  
  or natural disasters (such as an asteroid 
  striking Earth).  
  Fossil  The ancient remains or imprint of 
  a prehistoric organism preserved in rock.
  Fossilization  The process by which dead 
  organisms turn into fossils. Fossilization often 
  involves replacement of the original organism 
  with rock minerals.
  Gastropods  A class of invertebrates made 
  up of snails, slugs, and their many aquatic 
  relatives, such as cowries and limpets. 
  Genes  Chemical instructions encoded in 
  the DNA molecule. Genes control the way  
  all organisms grow and develop. They are 
  passed on from parents to their young. 
  Gondwana  A vast prehistoric supercontinent 
  that included South America, Africa, 
  Antarctica, Australia, and India. Gondwana 
  existed from Precambrian times until the 
  Jurassic Period, when these lands began to 
  move apart.
  Habitat  The place where a plant or animal 
  lives naturally.
  Hadrosaurids (duck-billed dinosaurs)  A 
  family of plant-eating dinosaur species with 
  duck-like beaks that lived during the 
  Cretaceous Period.
  Hagfish (Agnathan)  A kind of living 
  jawless fish.
  Herbivore  An animal that eats plants.
  Hominins  The family of apes that includes 
  humans and our closest relatives. 
  Homo erectus  A prehistoric member of the 
  human family that lived from 2 million years 
  ago to 100,000 years ago. Homo erectus 
  evolved in Africa but spread to Asia.
  Homo sapiens  The scientific name for 
  modern human (our own species).
  Hybrid  The offspring of parents from 
  two different species. 
  Ichthyosaurs  Prehistoric marine reptiles 
  that resembled dolphins or fish.
  Iguanodontians  Large, plant-eating 
  ornithopod dinosaurs that were common  
  in the Early Cretaceous.
  Invertebrates  Animals without backbones.
  Jawless fish (Agnathans)  A class of primitive 
  vertebrates that flourished mainly in Early 
  Palaeozoic times. They include extinct groups 
  and the living hagfish and lampreys.
  Jurassic  The middle period in the Mesozoic 
  Era, from 200 to 145 million years ago. 
  During the Jurassic Period, dinosaurs 
  dominated the land, the first birds evolved, 
  and mammals began to diversify.
  Juvenile  A young animal.
  Kin  Family – individuals that are genetically 
  related.
  Lamprey  A type of living jawless fish with 
  a round, sucker-like mouth.
  Lungfish  A type of fish that has both gills 
  and lungs and can breathe in water and air. 
  Lungfish appeared in the Devonian Period.
  Mammals  Warm-blooded, hairy vertebrates 
  that secrete milk and suckle their young. 
  Living mammals range from tiny shrews to 
  the blue whale (the largest creature ever) and 
  occupy a great variety of habitats. Mammals 
  originated in the Triassic Period. 
  Marine  Belonging to the sea (particularly 
  animals or plants).
  Marsupial  A type of mammal with a pouch 
  in which the young develop. Living examples 
  include kangaroos and wallabies. Marsupials 
  survive only in Australasia and the Americas.
  GLOSSARY
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  GLOSSARY
  Mastodons  An extinct group of large 
  mammals with trunks, tusks, and thick hair. 
  They were related to the elephants.
  Meganeura  A kind of giant dragonfly (more 
  correctly called a griffinfly) that lived in the 
  Carboniferous Period. Meganeura was possibly 
  the largest insect ever found on Earth.
  Metamorphosis  A major change in an 
  organism when it take on its adult form. The 
  change from caterpillar to butterfly is an 
  example of metamorphosis.
  Migration  A long-distance journey 
  undertaken by animals moving to new homes. 
  Many birds migrate in autumn in order to 
  spend winter in warmer countries. 
  Molluscs  A large group of invertebrate 
  species that includes slugs, snails, clams, 
  octopuses, and squids. Many molluscs 
  produce hard shells that fossilize easily, 
  making mollusc fossils common.
  Mosasaurs  Giant, sea-dwelling lizards that 
  lived during the Cretaceous Period. They were 
  fierce predators with slender bodies, long 
  snouts, and flipper-like limbs.
  Natural selection  The natural “weeding out” 
  of animals and plant that drives evolution. 
  Neanderthal (Homo neanderthalensis)  An 
  extinct species of hominin that is very closely 
  related to our own species. Neanderthals lived 
  in Europe and Asia during the last ice age.
  Neogene  The period of history from 23 
  million years ago to today. The Neogene 
  Period is divided into the Miocene, Pliocene, 
  Pleistocene, and Holocene epochs. 
  Nocturnal  Awake and active during the 
  night. Nocturnal animals include owls,  
  bats, and cats.
  Nothosaurs  A group of large, sea-dwelling 
  reptiles that lived in the Triassic Period. 
  Nothosaurs resembled seals and came  
  ashore to breed.
  Omnivore  An animal that eats both plant 
  and animal food. Examples include pigs, rats, 
  and human beings.
  Ordovician  The second period in the 
  Palaeozoic Era, from 488 to 444 million  
  years ago. All animals known from this  
  time lived in water. 
  Ornithischians (bird-hipped dinosaurs)  
  One of two major divisions into which  
  the dinosaur family tree is split (see also 
  Saurischians). Ornithischians were plant 
  eaters with beaked mouths.
  Ornithomimids (ostrich dinosaurs)  Tall, 
  slender, bird-like dinosaurs that were built 
  like ostriches. They were the fastest animals 
  on land in the Cretaceous Period.
  Paleogene  The first period in the Cenozoic 
  Era, from 65 to 23 million years ago. The 
  Paleogene is divided into the Paleocene, 
  Eocene, and Oligocene epochs.
  Palaeontology  The scientific study of 
  fossil plants and animals.
  Pampas  Treeless, grass-covered plains in 
  South America.
  Pangaea  A supercontinent that formed at the 
  end of the Palaeozoic Era. Pangaea contained 
  nearly all of Earth’s land and stretched from 
  the North Pole to the South Pole.
  Pelvis  The part of an animal’s skeleton 
  that forms the hips.
  Pelycosaurs  A group of large, reptile-like 
  animals that lived before the age of the 
  dinosaurs. Scientists believe that mammals 
  evolved from these creatures.
  Period  A very long unit of time, lasting 
  million of years. The Jurassic is a period.
  Permafrost  Permanently frozen ground 
  found in places such as northern Canada and 
  Siberia. Although the surface thaws out and 
  becomes boggy in summer, the deeper soil 
  remains frozen solid.
  Permian  The last period of the Palaeozoic 
  Era, from 299 to 251 million years ago.  
  The end of the Permian saw a worldwide 
  mass extinction in which most animal  
  species were wiped out.
  Placentals  Mammals whose unborn young 
  are nourished by a special organ called a 
  placenta. Placental mammals have replaced 
  marsupials in most parts of the world. 
  Placoderm (armoured fish)  A class of 
  prehistoric fish that had body armour formed 
  from plates of bone. They flourished in the 
  Devonian Period.
  Plesiosaurs  Large, prehistoric marine reptiles 
  that swam with flipper-shaped limbs. Many 
  had enormously long necks and tiny heads. 
  Others (called pliosaurs) had short necks and 
  huge heads with powerful, fang-lined jaws.
  Precambrian  The great span of time lasting 
  from Earth’s formation 4.6 billion years ago 
  to the start of the Cambrian Period 542 
  million years ago. For most of the 
  Precambrian, the only forms of life were 
  microscopic, single-celled organisms that  
  lived in water. 
  Predator  An animal that hunts, kills, and 
  eats other animals.
  Preservation  Keeping something, for 
  example a fossil, free from harm or decay.
  Prey  An animal that is hunted, killed, and 
  eaten by a predator.
  Primates  The group of mammals that 
  includes lemurs, monkeys, apes, and humans.
  Primitive  At an early stage of evolution. 
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  293
  GLOSSARY
  Pterosaurs  Huge flying reptiles that lived 
  during the age of the dinosaurs. The wings of 
  pterosaurs consisted of sheets of skin stretched 
  between the limbs.
  Ray-finned fish (Actinopterygii)  A major 
  class of fish that includes about 25,000 of 
  today’s fish species and many prehistoric 
  species. Ray-finned fish have fins consisting  
  of skin stretched over a fan of thin bones.
  Rays (Batoidea)  A group of 
  flat-bodied, cartilaginous fish 
  related to sharks. Examples 
  include stingrays and manta rays.
  Reptile  A cold-blooded animal with scaly 
  skin that typically lives on land and 
  reproduces by laying eggs. Lizards, snakes, 
  turtles, crocodiles, and dinosaurs are reptiles.
  Rodents  A group of mostly small mammals 
  that includes mice, rats, squirrels, and 
  porcupines. Rodents have sharp front teeth 
  used for gnawing nuts and seeds.
  Saurischians (lizard-hipped dinosaurs)  
  One of the two major divisions into which 
  the dinosaur family tree is split (see also 
  Ornithischians). All meat-eating dinosaurs 
  were saurischians.
  Sauropods  Gigantic, long-necked, plant-
  eating, saurischian dinosaurs. The sauropods 
  included the largest animals ever to walk  
  on Earth. 
  Savanna  Tropical grassland. Savannas 
  are often dotted with trees or patches  
  of woodland.
  Scutes  Bony plates with a horny covering set 
  in the skin of certain reptiles to protect them 
  from the teeth and claws of enemies.
  Sediment  Material deposited by wind, water, 
  or ice. Sediments such as sand, silt, and mud 
  build up on the sea floor and are eventually 
  turned into rock (sedimentary rock).
  Sedimentary rock  The type of rock in 
  which fossils are found.
  Silurian  The third period in the Palaeozoic 
  Era, from 444 to 416 million years ago. 
  Skull  The head’s bony framework that 
  protects the brain, eyes, ears, and nasal 
  passages.
  Species  A type of animal of plant. Examples 
  of species include lions, human beings, and 
  apple trees. Individual in a species can breed 
  with each other.
  Spinosaurids  A family of huge dinosaurs 
  of the Cretaceous Period that had sail-like 
  structures on their backs.
  Stegosaurs  Four-legged, plant-eating 
  dinosaurs with two rows of tall bony plates 
  and/or spines running down the back.
  Supercontinent  A prehistoric landmass 
  containing two or more major continental 
  plates. Examples include Gondwana and 
  Pangaea.
  Tetrapod  A vertebrate with four limbs 
  (arms, legs, or wings). All amphibians, 
  reptiles, mammals, and birds are tetrapods. 
  Snakes are also tetrapods because they 
  evolved from ancestors with four limbs.
  Therizinosaurs  A group of bizarre-looking 
  dinosaurs that lived in the Cretaceous Period. 
  Therizinosaurs were tall with small heads, 
  stumpy feet, and pot bellies.
  Theropods  A large branch of the dinosaur 
  family tree made up mostly of predators. 
  Theropods typically had sharp teeth and 
  claws. They ranged from hen-sized creatures 
  to the colossal Tyrannosaurus.
  Titanosaurs  Very large, four-legged, 
  plant-eating dinosaurs. The titanosaurs  
  were sauropods and included perhaps  
  the largest land animals ever.
  Triassic  The first period in the Mesozoic Era, 
  from 251 to 200 million years ago. Dinosaurs 
  emerged in the Triassic Period. 
  Trilobites  Prehistoric sea creatures with 
  external skeletons divided lengthwise into 
  three lobes. Variations in the shape and 
  features of trilobite fossils are an accurate 
  indicator of the age of the sedimentary rocks 
  in which they are found. 
  Vertebrae  The linked bones forming the 
  backbone of a vertebrate animal. 
  Vertebrates  Animals with an internal 
  bony or cartilaginous skeleton including 
  a skull and a backbone. Fish, 
  amphibians, reptiles, birds, and 
  mammals are all vertebrates.
  Warm-blooded  Animals that 
  maintain a constant internal  
  body temperature are described  
  as warm-blooded. Mammals and birds are 
  warm-blooded, whereas fish and reptiles  
  are cold-blooded. 
  Wingspan  The distance from the tip of 
  one wing to the tip of the other when  
  both wings are outstretched.
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  302
  Dorling Kindersley would like to thank 
  Madhavi Singh for proofreading and Poppy 
  Joslin for design assistance.
  The publisher would also like to thank 
  the following for their kind permission to 
  reproduce their photographs (Key: a-above; 
  b-below/bottom; c-centre; f-far; l-left; 
  r-right; t-top).
  1 Getty Images: Iconica / Philip and Karen 
  Smith (background). 2 Alamy Images: Phil 
  Degginger (4). Corbis: Frans Lanting (1); 
  Science Faction / Norbert Wu (6). Dorling 
  Kindersley: Colin Keates / courtesy of the 
  Natural History Museum, London (2); 
  Barrie Watts (7). 3 Ardea: Pat Morris (5/l). 
  Corbis: Frans Lanting (3/r); Paul Souders 
  (8/r). Dorling Kindersley: Jon Hughes 
  (7/r, 2/l). Getty Images: AFP (2/r); Stone / 
  Howard Grey (5/r); WireImage / Frank 
  Mullen (4/l). Science Photo Library: (1/l); 
  Richard Bizley (1/r); Christian Darkin 
  (4/r); Mark Garlick (7/l). 4 Ardea: Pat 
  Morris (bl). Getty Images: Stone / Howard 
  Grey (clb). Science Photo Library: 
  Christian Darkin (br). 4-5 Dorling 
  Kindersley: Andy Crawford / courtesy of 
  the Royal Tyrrell Museum of Palaeontology, 
  Alberta, Canada. 5 Dorling Kindersley: 
  Andrew Nelmerm / courtesy of the Royal 
  British Columbia Museum, Victoria, 
  Canada (bl). Getty Images: AFP (br). 6-7 
  Alamy Images: Phil Degginger. 7 Dorling 
  Kindersley: Colin Keates / courtesy of the 
  Natural History Museum, London (tc). 8 
  Corbis: Arctic-Images (t). 9 Alamy 
  Images: AF Archive (cla). Corbis: Frans 
  Lanting (br); Bernd Vogel (t); George 
  Steinmetz (cra); Visuals Unlimited / Dr. 
  Terry Beveridge (crb). 11 Corbis: The 
  Gallery Collection (tl). Dorling 
  Kindersley: Colin Keates / courtesy of the 
  Natural History Museum, London (cra). 
  12 Corbis: Douglas Peebles (bl). Getty 
  Images: Science Faction Jewels / Louie 
  Psihoyos (tr). 14 Science Photo Library: 
  Richard Bizley (cr); Walter Myers (tr). 16 
  Dorling Kindersley: Colin Keates / 
  courtesy of the Natural History Museum, 
  London (t). 17 Corbis: Sygma / Didier 
  Dutheil (tr). Dorling Kindersley: Barrie 
  Watts (bl). 18-19 Getty Images: Science 
  Faction Jewels / Louie Psihoyos. 20 Corbis: 
  Sygma / Didier Dutheil (l, br). Science 
  Photo Library: Ted Kinsman (tr). 21 
  Corbis: Sygma / Didier Dutheil (tl, tr, cra, 
  crb, br). 22-23 Harry Wilson. . : (main 
  illustration). 23 Corbis: Momatiuk - 
  Eastcott (crb). Photolibrary: OSF / Robert 
  Tyrrell (br). 24 Getty Images: Stone / 
  Howard Grey (l/sidebar). 24-25 Ardea: Pat 
  Morris. 25 Alamy Images: John T. Fowler 
  (cr). 26 Alamy Images: Nicholas Bird (bc); 
  H. Lansdown (br). Corbis: Frank Krahmer 
  (bl); Science Faction / Norbert Wu (cla). 27 
  Alamy Images: WaterFrame (br). Corbis: 
  Gary Bell (bc); Science Faction / Stephen 
  Frink (clb); Stephen Frink (cr); Paul 
  Edmondson (bl). Getty Images: Minden 
  Pictures / Foto Natura / Ingo Arndt (tl). 28 
  Corbis: Frans Lanting (bl). 29 J. Gehling, 
  South Australian Museum: (tr). 30 Alamy 
  Images: Kevin Schafer (br). Getty Images: 
  National Geographic / O. Louis 
  Mazzatenta (c). 31 Science Photo Library: 
  Alan Sirulnikoff (cr). 32 courtesy of the 
  Smithsonian Institution: (cl). 35 Natural 
  History Museum, London: (br). 37 
  Ardea: Francois Gohier (cl). Dorling 
  Kindersley: Harry Taylor / courtesy of the 
  Royal Museum of Scotland, Edinburgh 
  (bl). 41 Getty Images: Comstock Images 
  (tr). 43 Corbis: Jeffrey L. Rotman (br); 
  Visuals Unlimited / Wim van Egmond (tr). 
  45 Corbis: Frank Lane Picture Agency / 
  Douglas P. Wilson (cb); Visuals Unlimited / 
  Ken Lucas (tl). 46-47 Alamy Images: Kate 
  Rose / Peabody Museum, New Haven, 
  Connecticut. 46 Natural History 
  Museum, London: (bl). 47 Corbis: 
  Michael & Patricia Fogden (br). Prof. J.W. 
  Schneider/TU Bergakademie Freiberg: 
  (tr). 48 Alamy Images: John T. Fowler (tr). 
  Corbis: Tom Bean (bl). Science Photo 
  Library: Noah Poritz (t). 50-51 naturepl.
  com: Jean E. Roche. 51 Dorling 
  Kindersley: Frank Greenaway / courtesy of 
  the Natural History Museum, London (br). 
  52-53 Getty Images: Stone / Howard 
  Grey. 54 Natural History Museum, 
  London: Graham Cripps. 55 akg-images: 
  Gilles Mermet (tr). NHPA / Photoshot: 
  Ken Griffiths (br). 57 Getty Images: The 
  Image Bank / Philippe Bourseiller (br). 
  58-59 Ardea: John Cancalosi. 58 Alamy 
  Images: Danita Delimont (c); Scenics & 
  Science (r). 60 Dorling Kindersley: Colin 
  Keates / courtesy of the Natural History 
  Museum, London (cra/Giant cerith). Getty 
  Images: Mike Kemp (bl/snail). 62 Dorling 
  Kindersley: Harry Taylor / courtesy of the 
  Royal Museum of Scotland, Edinburgh 
  (sidebar). 63 Dorling Kindersley: Harry 
  Taylor / courtesy of the Royal Museum of 
  Scotland, Edinburgh (cl). Photolibrary: 
  Oxford Scientific (OSF) / David M. 
  Dennis (c). 64 Corbis: All Canada Photos / 
  Ron Erwin (bc); Frans Lanting (br). 65 
  Ardea: Ken Lucas (ca). Dorling 
  Kindersley: Andy Crawford / courtesy of 
  the Royal Tyrrell Museum of Palaeontology, 
  Alberta, Canada (tr); David Peart (br). 66 
  Alamy Images: blickwinkel (br). 67 
  Dorling Kindersley: Harry Taylor / 
  courtesy of the Royal Museum of Scotland, 
  Edinburgh (tr); Harry Taylor / courtesy of 
  the Hunterian Museum (University of 
  Glasgow) (bl). 68 Alamy Images: All 
  Canada Photos / Royal Tyrrell Museum, 
  Drumheller, Alta, Canada (c). 70 Dorling 
  Kindersley: Colin Keates / courtesy of the 
  Natural History Museum, London (b). 71 
  Dorling Kindersley: Colin Keates / 
  courtesy of the Natural History Museum, 
  London (tl, crb). Science Photo Library: 
  Christian Darkin (b). 73 Corbis: Layne 
  Kennedy (tr); Louie Psihoyos (br). 75 
  Corbis: Visuals Unlimited (b). Dorling 
  Kindersley: Neil Fletcher (c) Oxford 
  University Museum of Natural History (cr); 
  Harry Taylor / courtesy of the Royal 
  Museum of Scotland, Edinburgh (cl); 
  Colin Keates / courtesy of the Natural 
  History Museum, London (tr). 77 Alamy 
  Images: PetStockBoys (tl). Dorling 
  Kindersley: Harry Taylor / courtesy of the 
  Natural History Museum, London (tr). 79 
  Dorling Kindersley: Colin Keates / 
  courtesy of the Natural History Museum, 
  London (tr). Getty Images: Taxi / Peter 
  Scoones (br). 81 Alamy Images: B. 
  Christopher (bl). Corbis: Gallo Images / 
  Anthony Bannister (tr). Dorling 
  Kindersley: Jan van der Voort (crb). Dr 
  Howard Falcon-Lang: (br). 82 Alamy 
  Images: WaterFrame (cl). 83 Dorling 
  Kindersley: Steve Gorton / Richard 
  Hammond - modelmaker / courtesy of 
  Oxford University Museum of Natural 
  History (cl); Colin Keates / courtesy of the 
  Natural History Museum, London (tl). 84 
  Science Photo Library: Visuals Unlimited 
  / Ken Lucas (t). 86 Alamy Images: 
  Realimage (tl). 87 Alamy Images: 
  botanikfoto / Steffen Hauser (clb). Dorling 
  Kindersley: Colin Keates / courtesy of the 
  Natural History Museum, London (tc). 88 
  Corbis: Arctic-Images (l). 89 Corbis: 
  Science Faction / Louie Psihoyos (tr). 92 
  Corbis: Sygma / Vo Trung Dung (b/
  background). 95 Photolibrary: Oxford 
  Scientific (OSF) / David M. Dennis (cl). 
  96-97 Corbis: Mark A. Johnson 
  (background). 96 Luigi Chiesa: (bl). 98 
  Corbis: Kevin Schafer (b). 98-99 Dorling 
  Kindersley: (c) David Peart (background). 
  102-103 Science Photo Library: John 
  Foster. 102 Corbis: Sygma / Vo Trung 
  Dung (bl). 103 Science Photo Library: 
  Victor Habbick Visions (cl). 104 Dorling 
  Kindersley: David Peart (background). 
  105 Corbis: In Pictures / Mike Kemp (br). 
  107 Getty Images: AFP / Valery Hache 
  (cl). 108 Natural History Museum, 
  London: Berislav Krzic (b). 110 Alamy 
  Images: Pictorial Press Ltd (b). 111 
  Dorling Kindersley: Colin Keates / 
  courtesy of the Natural History Museum, 
  London (tr). Science Photo Library: (tl); 
  Michael Marten (tc). Wellcome Images: 
  Wellcome Library, London (br). 113 
  Alamy Images: Kevin Schafer (t). 114-115 
  Alamy Images: Paul Kingsley. 114 Dorling 
  Kindersley: John Downes / John Holmes 
  - modelmaker / courtesy of the Natural 
  History Museum, London (sidebar). 115 
  Dorling Kindersley: Colin Keates / 
  courtesy of the Natural History Museum, 
  London (cl). Science Photo Library: Joe 
  Tucciarone (cr). 116-117 Corbis: Michael 
  S. Yamashita. 118 Science Photo Library: 
  Roger Harris (br). 119 Dorling 
  Kindersley: Jon Hughes (tl, bl, tr). 120 
  Dorling Kindersley: Andy Crawford / 
  courtesy of the Royal Tyrrell Museum of 
  Palaeontology, Alberta, Canada (cl). 122-
  133 Dorling Kindersley: Nigel Hicks / 
  courtesy of the Lost Gardens of Heligan 
  (background). 125 Getty Images: National 
  Geographic Creative / Jeffrey L. Osborn 
  (cl). 126-127 Corbis: Inspirestock 
  (background). 127 Dorling Kindersley: 
  Colin Keates / courtesy of the Natural 
  History Museum, London (bl). Wikipedia, 
  The Free Encyclopedia: (br). 128 Dorling 
  Kindersley: Jon Hughes; Colin Keates / 
  courtesy of the Natural History Museum, 
  London (b). 130 Getty Images: Panoramic 
  Images (t/background). 131 Dorling 
  Kindersley: Andy Crawford / courtesy of 
  the Royal Tyrrell Museum of Palaeontology, 
  Alberta, Canada (bl); Courtesy of the Royal 
  Tyrrell Museum of Palaeontology, Alberta, 
  Canada (ca). Natural History Museum, 
  London: Berislav Krzic (br). 132-133 
  Corbis: Louie Psihoyos. 133 Dorling 
  Kindersley: (c) Rough Guides / Alex 
  Wilson (tr). U.S. Geological Survey: (br). 
  135 Dorling Kindersley: Lynton Gardiner 
  / courtesy of the American Museum of 
  Natural History (tr, br). 137 Dorling 
  Kindersley: Lynton Gardiner / courtesy of 
  the American Museum of Natural History 
  (tr, c). 141 Dorling Kindersley: Tim 
  Ridley / courtesy of the Leicester Museum 
  Acknowledgements
  ACKNOWLEDGEMENTS
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  303
  ACKNOWLEDGEMENTS
  Alean (tr); Richard Bizley (bl); Gary Hincks 
  (br). 237 Corbis: David Muench (tr). 
  Science Photo Library: Gary Hincks (br, 
  bl). 239 Dorling Kindersley: Bedrock 
  Studios (b). 240-241 Natural History 
  Museum, London: Michael R. Long . 240 
  Alamy Images: Martin Shields (bl). 241 
  Alamy Images: Martin Shields (tl). Pyry 
  Matikainen. 242 Alamy Images: Ryan M. 
  Bolton (tl). Dorling Kindersley: Jon 
  Hughes (r). 244 Alamy Images: Elvele 
  Images Ltd. 245 Dorling Kindersley: 
  Bedrock Studios (cr). 247 Alamy Images: 
  blickwinkel (br). 248-249 Dorling 
  Kindersley: Bedrock Studios. 248 Getty 
  Images: Popperfoto / Bob Thomas (b). 250 
  Corbis: Carl & Ann Purcell (background). 
  Dorling Kindersley. 251 Corbis: Kevin 
  Schafer (br). 255 Science Photo Library: 
  Walter Myers (bl). 256-257 Corbis: Annie 
  Griffiths Belt. 257 Science Photo Library: 
  Larry Miller (b). 258 Getty Images: Gallo 
  Images / Ray Ives (r/background). 259 
  Alamy Images: vario images GmbH & 
  Co.KG (br). Dorling Kindersley: Dave 
  King / courtesy of the Natural History 
  Museum, London (tr, c); Harry Taylor / 
  courtesy of the Natural History Museum, 
  London (bl). 260-261 Science Photo 
  Library: Christian Darkin. 261 Ardea: 
  Masahiro Iijima (br). Photolibrary: Goran 
  Burenhult; (tr). 262 Alamy Images: ITAR-
  TASS Photo Agency (b). Corbis: Science 
  Faction / Steven Kazlowski (b/background). 
  262-263 Alamy Images: Gerner Thomsen 
  (c). 263 Alamy Images: Arcticphoto (t). 
  Getty Images: AFP / RIA Novosti (b). 264 
  Corbis: Reuters / Marcos Brindicci (bl). 
  265 Alamy Images: The Natural History 
  Museum (tr). Corbis: Buddy Mays (br). 
  267 Dorling Kindersley: Bedrock Studios 
  (cr, bl). 268 Alamy Images: Niels Poulsen 
  mus (b). Ardea: Duncan Usher (tl). 269 
  Alamy Images: blickwinkel (tr). 270-271 
  Getty Images: National Geographic / Sisse 
  (br). 145 Dorling Kindersley: Bruce 
  Cowell / courtesy of Queensland Museum, 
  Brisbane, Australia (t). 146 Corbis: Rune 
  Hellestad (b). 148 Dorling Kindersley: 
  Andy Crawford / courtesy of the Institute 
  of Geology and Palaeontology, Tubingen, 
  Germany (cl, tr). 150 Alamy Images: 
  Fabian Gonzales Editorial (t/background). 
  Getty Images: The Image Bank / Don 
  Smith (b/background). 152-153 Dorling 
  Kindersley: Philippe Giraud (background); 
  Steve Gorton / John Holmes - modelmaker. 
  153 Dorling Kindersley: Steve Gorton / 
  Robert L. Braun - modelmaker (t). 157 
  Corbis: Cameron Davidson (tr); Louie 
  Psihoyos (bl). Dorling Kindersley: Lynton 
  Gardiner / courtesy of the Carnegie 
  Museum of Natural History, Pittsburgh 
  (br). 158-159 Getty Images: Siri and Jeff 
  Berting (background). 158 Corbis: Bob 
  Krist (bl). 160 Corbis: Joson (background). 
  163 Dorling Kindersley: Jon Hughes (ca). 
  Science Photo Library: Walter Myers (br). 
  164 Alamy Images: Alberto Paredes (r). 
  165 Alamy Images: Paul Kingsley (br); 
  Tony Waltham / Robert Harding Picture 
  Library Ltd (crb). Corbis: Science Faction / 
  Louie Psihoyos (cl). Dorling Kindersley: 
  Colin Keates / courtesy of the Natural 
  History Museum, London (tc). Science 
  Photo Library: Sinclair Stammers (bl). 
  169 Corbis: Louie Psihoyos (cr). 170-171 
  Corbis: Aurora Photos / Randall Levensaler 
  Photography (b/background). 171 Dorling 
  Kindersley: Colin Keates / courtesy of 
  Senckenberg, Forschungsinstitut und 
  Naturmuseum, Frankfurt (tl). 172-173 
  Ardea: Andrey Zvoznikov (background). 
  174-175 Getty Images: Iconica / Philip 
  and Karen Smith (background). 175 
  Dorling Kindersley: Jon Hughes (br). 176 
  Mike Hettwer: (br). 177 Corbis: Sygma / 
  Didier Dutheil (bl, bc, br). 178-179 
  Dorling Kindersley: Jon Hughes. 179 
  Dorling Kindersley: Andy Crawford / 
  courtesy of Staatliches Museum fur 
  Naturkunde Stuttgart (bl); Steve Gorton / 
  Richard Hammond - modelmaker / 
  courtesy of the American Museum of 
  Natural History (br). 181 Ardea: Francois 
  Gohier (bl). 182-183 Getty Images: 
  Willard Clay Photography, Inc. 
  (background). 184-185 Corbis: 
  amanaimages / Mitsushi Okada 
  (background). 185 Dorling Kindersley: 
  Colin Keates / courtesy of the Natural 
  History Museum, London (tr). 186 
  Dorling Kindersley: Andy Crawford / 
  courtesy of the Royal Tyrrell Museum of 
  Palaeontology, Alberta, Canada (tl). 187 
  Corbis: Science Faction / Louie Psihoyos 
  (tr). 188-189 Getty Images: WireImage / 
  Frank Mullen. 189 Corbis: George 
  Steinmetz (bl, tr, cr, br). 190 Corbis: Louie 
  Psihoyos (tr). 190-191 Corbis: Owen 
  Franken (background). 191 Corbis: Louie 
  Psihoyos (tl). 195 Corbis: Louie Psihoyos 
  (br). 196 Science Photo Library: Roger 
  Harris (bl). 197 Dorling Kindersley: Gary 
  Ombler / (c) Luis Rey 
  - modelmaker (tr). 
  Getty Images: Science 
  Faction Jewels / Louie Psihoyos 
  (tc). 198-199 Corbis: Nick Rains 
  (background). 199 Dorling Kindersley: 
  Lynton Gardiner (c) Peabody Museum of 
  Natural History, Yale University (tr). 200-
  201 Getty Images: Spencer Platt. 201 
  Science Photo Library: Christian Darkin 
  (t). 202-203 Reuters: Mike Segar. 203 
  Corbis: Grant Delin (b). 206 Corbis: 
  Jonathan Blair (b). Science Photo Library: 
  Mark Garlick. 207 Nicholas/http://
  commons.wikimedia.org/wiki/
  File:Western-Ghats-Matheran.jpg: (cr). 
  Science Photo Library: Joe Tucciarone (b); 
  D. Van Ravenswaay (tl). 208 Corbis: 
  Layne Kennedy (bl). Dorling Kindersley: 
  Colin Keates / courtesy of the Natural 
  History Museum, London (br). 209 
  Dorling Kindersley: Jon Hughes (br). 210 
  Dorling Kindersley: Jon Hughes / 
  Bedrock Studios. 211 Corbis: National 
  Geographic Society (tr). Dorling 
  Kindersley: Jon Hughes (cr). 212 John 
  Scurlock: (bl). 213 courtesy of the 
  Smithsonian Institution. 214 Dorling 
  Kindersley: Philip Dowell (sidebar). 215 
  Dorling Kindersley: Andrew Nelmerm / 
  courtesy of the Royal British Columbia 
  Museum, Victoria, Canada (bc). Science 
  Photo Library: Pascal Goetgheluck (br). 
  216 Ardea: Steve Downer (tc). Corbis: 
  Frans Lanting (tr); Visuals Unlimited / 
  Thomas Marent (bc); Momatiuk - Eastcott 
  (br). Getty Images: AFP / Sam Yeh (cl). 
  217 Corbis: Paul Souders (cra); Keren Su 
  (bl). Dorling Kindersley: courtesy of the 
  Booth Museum of Natural History, 
  Brighton (tl); Nigel Hicks (bc). 218 
  Corbis: Lester V. Bergman (tc). Dorling 
  Kindersley: Colin Keates / courtesy of the 
  Natural History Museum, London (bl). 
  219 Getty Images: Ken Lucas (cl). 221 
  Dorling Kindersley: Harry Taylor / 
  courtesy of York Museums Trust (Yorkshire 
  Museum) (b). 224 Corbis: Radius Images 
  (r). Getty Images: National Geographic / 
  Jonathan Blair (tl). Science Photo Library: 
  Maria e Bruno Petriglia (bl). 225 Corbis: 
  Ecoscene / Wayne Lawler (clb); Karl-Heinz 
  Haenel; Stock Photos / Bruce Peebles (bl, 
  bc); Frans Lanting (tl). Getty Images: 
  Stockbyte / Joseph Sohm-Visions of 
  America (cla). 226 Dorling Kindersley: 
  Lindsey Stock (background). 227 Corbis: 
  Frans Lanting (tr). Dorling Kindersley: 
  Bedrock Studios (tl); Colin Keates / 
  courtesy of the Natural History Museum, 
  London (bl). 228-229 naturepl.com: Dave 
  Watts. 229 Corbis: epa / Dave Hunt (t); In 
  Pictures / Barry Lewis (br). 230 Science 
  Photo Library: Christian Darkin. 231 
  Getty Images: Photonica / Theo Allofs 
  (cra). 232 Corbis: Bob Krist (background). 
  233 Alamy Images: blickwinkel (br). 
  Getty Images: Ken Lucas (tr). 234 
  Dorling Kindersley: Colin Keates / 
  courtesy of the Natural History Museum, 
  London (cl). 235 Dorling Kindersley: Jon 
  Hughes / Bedrock Studios (tr). Getty 
  Images: De Agostini Picture Library (cr). 
  Science Photo Library: Mauricio Anton 
  (br). 236-237 Corbis: Jonathan Andrew. 
  236 Science Photo Library: Dr Juerg 
  Brimberg. 270 Getty Images: Stone / 
  Robert Frerck (br); Time & Life Pictures / 
  Ralph Morse (bl). Robert Gunn: (tr). 271 
  French Ministry of Culture and 
  Communication, Regional Direction for 
  Cultural Affairs - Rhône-Alpes region 
  - Regional department of archaeology: 
  (bl). Getty Images: AFP (br). 274 Getty 
  Images: Gallo Images / Latitudestock (b). 
  275 Corbis: Denis Scott (b). 276 Getty 
  Images: AFP / Stan Honda. 277 Dorling 
  Kindersley: Harry Taylor / courtesy of the 
  Natural History Museum, London (tl). 278 
  Science Photo Library: Mauricio Anton. 
  279 Corbis: Frans Lanting (bl); Sygma / 
  Régis Bossu (tl). naturepl.com: Karl 
  Ammann (br). Science Photo Library: 
  John Reader (tr). 280 Science Photo 
  Library: Mauricio Anton. 281 Corbis: 
  Larry Williams (tr). 282 Corbis: epa / 
  Federico Gambarini. Dorling Kindersley: 
  Rough Guides (background). 283 Corbis: 
  Reuters / Nikola Solic (tl). Science Photo 
  Library: Pascal Goetgheluck (bl). 284 
  Science Photo Library: Christian Darkin 
  (r). 285 Alamy Images: Sabena Jane 
  Blackbird (ca). Corbis: Frans Lanting (bl); 
  Sygma / Kevin Dufy (cb); Buddy Mays 
  (br). The Kobal Collection: Hammer (t). 
  286-287 Getty Images: Gallo Images / 
  Andrew Bannister. 288-289 Getty Images: 
  Gallo Images / Peter Chadwick. 290 Getty 
  Images: Gallo Images / Peter Chadwick 
  (sidebar). 294 Dorling Kindersley: Dave 
  King / Jeremy Hunt at Centaur Studios - 
  modelmaker (bl). 300 Dorling Kindersley: 
  Andy Crawford / courtesy of the Royal 
  Tyrrell Museum of Palaeontology, Alberta, 
  Canada (bl). 304 Corbis: Frans Lanting
  Jacket images: Front: Alamy Images: 
  Javier Etcheverry br; Corbis: Louie 
  Psihoyos t; Science Photo Library: 
  Chris Butler bl, Tom McHugh fbr; Back: 
  Dorling Kindersley: Andrew Nelmerm 
  / courtesy of the Royal British Columbia 
  Museum, Victoria, Canada cr; Getty 
  Images: Photographer’s Choice / Colin 
  Anderson fbr; Science Photo Library: 
  Christian Darkin t, fbl; Front Flap: Dorling 
  Kindersley: Jon Hughes
  All other images © Dorling Kindersley
  For further information see: www.
  dkimages.com
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
  (c) 2011 Dorling Kindersley. All Rights Reserved.
  
SOURCE: textdata/thevault/Collections/Kid Friendly/2. Kid Inspiration & Fun RPG-related Crafts & Activities/Kid Inspiration & Art Books/DK - Dinosaurs.pdf