Instruct: Given a question, retrieve relevant documents that answer the question.
Query: What was the largest dinosaur?
The "World's Largest Dinosaur" is the name of a model "Tyrannosaurus rex" located in the town of Drumheller in the Canadian province of Alberta. Built of fiberglass and steel, has a height of and a length of , considerably larger than the largest known specimens of the actual dinosaur which reached up to in length, and was up to tall at the hips. The dinosaur was built while former mayor Phil Bryant was in his term.
"Sinosauropteryx" was a small theropod with an unusually long tail and short arms. The longest known specimen reaches up to in length, with an estimated weight of It was a close relative of the similar but older genus "Compsognathus", both genera belonging to the family Compsognathidae. Only one species of "Sinosauropteryx" has been named: "S. prima", meaning "first" in reference to its status as the first feathered non-avialian dinosaur species discovered. Three specimens have been described. The third specimen previously assigned to this genus represents either a second, as-yet unnamed species or a distinct, related genus.
Pteranodon (; from Greek πτερόν ( pteron, "wing") and ἀνόδων (anodon, "toothless") is a genus of pterosaur that included some of the largest known flying reptiles, with wingspans over 8 meters (26 feet). They lived during the late Cretaceous geological period of North America in present-day Kansas, Alabama, Nebraska, Wyoming, and South Dakota. More fossil specimens of "Pteranodon" have been found than any other pterosaur, with about 1,200 specimens known to science, many of them well preserved with nearly complete skulls and articulated skeletons. It was an important part of the animal community in the Western Interior Seaway.
Methods used to estimate the mass of large male "Pteranodon" specimens (those with wingspans of about 7 meters) have been notoriously unreliable, producing a wide range of estimates from as low as to as high as . In a review of pterosaur size estimates published in 2010, researchers Mark Witton and Mike Habib demonstrated that the latter, largest estimates are almost certainly incorrect given the total volume of a "Pteranodon" body, and could only be correct if the animal "was principally aluminium". Witton and Habib considered the methods used by researchers who obtained smaller mass estimates equally flawed. Most have been produced by scaling modern animals such as bats and birds up to "Pteranodon" size, despite the fact that pterosaurs have vastly different body proportions and soft tissue anatomy from any living animal.
The Late Cretaceous Epoch spans from 100 million to 66 million years ago. The Late Cretaceous featured a cooling trend that would continue into the Cenozoic Era. Eventually, tropical ecology was restricted to the equator and areas beyond the tropic lines featured extreme seasonal changes of weather. Dinosaurs still thrived as new species such as "Tyrannosaurus", "Ankylosaurus", "Triceratops" and Hadrosaurs dominated the food web. Whether or not Pterosaurs went into a decline as birds radiated is debated, however many families survived until the end of the Cretaceous, alongside new species such as the gigantic "Quetzalcoatlus". Marsupials evolved within the large conifer forests as scavengers. In the oceans, Mosasaurs ruled the seas to fill the role of the ichthyosaurs, and huge plesiosaurs, such as "Elasmosaurus", evolved. Also, the first flowering plants evolved. At the end of the Cretaceous, the Deccan Traps and other volcanic eruptions were poisoning the atmosphere. As this was continued, it is thought that a large meteor smashed into Earth, creating the Chicxulub Crater creating the event known as the K-T Extinction, the fifth and most recent mass extinction event, during which 75% of life on Earth became extinct, including all non-avian dinosaurs. Every living thing with a body mass over 10 kilograms became extinct, and the age of the dinosaurs came to an end.
Josephoartigasia monesi, an extinct species of South American caviomorph rodent, is the largest rodent known, and lived from about 4 to 2 million years ago during the Pliocene to early Pleistocene. The species is one of two in the genus "Josephoartigasia", the other being "J. magna". "J. monesi" is sometimes called the giant pacarana, after its closest living relative, the pacarana ("Dinomys branickii") in the family Dinomyidae. The species may have weighed a ton, considerably larger than any living rodent.
Yellow-footed tortoises are a large species – fifth-largest overall and third-largest mainland species, after the Aldabra giant tortoise ("Aldabrachelys gigantea"), Galapagos giant tortoise ("Chelonoidis nigra"), African spurred tortoise, and Asian forest tortoise. Typical sizes average 40 cm (15.75 in), but much larger specimens are common. The largest know specimen is a female that was 94 cm (37 in) long. They closely resemble the red-footed tortoise, and can sometimes be difficult to tell apart, especially as a preserved specimen, which led to quite a bit of confusion over the names and ranges.
The giant hutias are an extinct group of large rodents known from fossil and subfossil material in the West Indies. One species, "Amblyrhiza inundata", is estimated to have weighed between , big specimens being as large as an American black bear. This is twice as large as the capybara, the largest rodent living today, but still much smaller than "Josephoartigasia monesi", the largest rodent known. These animals were probably used as a food source by aboriginal humans. All giant hutias are in a single family, Heptaxodontidae, which contains no living species; this grouping seems to be paraphyletic and artificial, however.
The museum's five rooms shows paleontological finds from the Besano area, including the "Besanosaurus", a type of ichthyosaur from the middle Triassic period.
The 6 meter "Besanosaurus leptorhynchus" discovered in 1993 is the biggest sea reptile fossil found in Italy, and was probably a pregnant female.
Since 2001 the museum has also housed the remains of a "Saltriosaurus", discovered in a quarry in Saltrio, which is the first big carnivorous dinosaur found in Lombardia.
The largest living snakes in the world, measured either by length or by weight, are various members of the Boidae and Pythonidae families. They include anacondas, pythons, and boa constrictors, which are all non-venomous constrictors. The longest "venomous" snake, with a length up to , is the king cobra, and the heaviest venomous snake is likely to be the Gaboon viper (which also has the longest fangs and delivers the largest amount of venom) or possibly the Eastern diamondback rattlesnake – all three of which reach maximum weights in the range of .
The Early Cretaceous Epoch spans from 145 million to 100 million years ago. The Early Cretaceous saw the expansion of seaways, and as a result, the decline and extinction of sauropods (except in South America). Many coastal shallows were created, and that caused ichthyosaurs to die out. Mosasaurs evolved to replace them as apex species of the seas. Some island-hopping dinosaurs, like "Eustreptospondylus", evolved to cope with the coastal shallows and small islands of ancient Europe. Other dinosaurs, such as "Carcharodontosaurus" and "Spinosaurus", rose to fill the empty space that the Jurassic-Cretaceous extinction had created. Of the most successful would be the "Iguanodon" which spread to every continent. Seasons came back into effect and the poles grew seasonally colder. Dinosaurs such as the "Leaellynasaura" inhabited the polar forests year-round, while many dinosaurs, such as the "Muttaburrasaurus", migrated there during summer . Since it was too cold for crocodiles, it was the last stronghold for large amphibians, such as the "Koolasuchus". In this epoch Pterosaurs reached their maximum diversity and grew larger, as species like "Tapejara" and "Ornithocheirus" took to the skies. The first true birds evolved, possibly sparking competition between them and the pterosaurs.
Gigantopithecus (from the Ancient Greek ' "giant", and ' "ape") is an extinct genus of ape that existed from perhaps nine million years to as recently as one hundred thousand years ago, at the same period as "Homo erectus" would have been dispersed, in what is now India, Vietnam, China and Indonesia placing "Gigantopithecus" in the same time frame and geographical location as several hominin species. The primate fossil record suggests that the species "Gigantopithecus blacki" were the largest known primates that ever lived, standing up to and weighing as much as , although some argue that it is more likely that they were much smaller, at roughly in height and in weight.
The largest confirmed saltwater crocodile on record drowned in a fishing net in Papua New Guinea in 1979, its dried skin plus head measured long and it was estimated to have been when accounting for shrinkage and a missing tail tip. However, according to evidence, in the form of skulls coming from some of the largest crocodiles ever shot, the maximum possible size attained by the largest members of this species is considered to be . A governmental study from Australia accepts that the very largest members of the species are likely to measure in length and weigh . Furthermore, a research paper on the morphology and physiology of crocodilians by the same organisation estimates that saltwater crocodiles reaching sizes of would weigh around . Due to extensive poaching during the 20th century, such individuals are extremely rare today in most areas, as it takes a long time for the crocodiles to attain those sizes. Also, a possible earlier presence of particular genes may have led to such large-sized saltwater crocodiles, genes that were ultimately lost from the overall gene pool due to extensive hide and trophy hunting in the past. However, with recent restoration of saltwater crocodile habitat and reduced poaching, the number of large crocodiles is increasing, especially in Odisha. This species is the only extant crocodilian to regularly reach or exceed . A large male from Philippines, named Lolong, was the largest saltwater crocodile ever caught and placed in captivity. He was 20 ft 3 in (6.17 m), and weighed 2,370 lbs (1,075 kg). Believed to have eaten two villagers, Lolong was captured on 3 September 2011, and died in captivity on 10 February 2013.
Yutyrannus (meaning "feathered tyrant") is a genus of tyrannosauroid dinosaurs which contains a single known species, Yutyrannus huali. This species lived during the early Cretaceous period in what is now northeastern China. Three fossils of "Yutyrannus huali"—all found in the rock beds of Liaoning Province—are currently the largest-known dinosaur specimens that preserve direct evidence of feathers.
Cassius is a male saltwater crocodile ("Crocodylus porosus") recognized by the Guinness World Records as the world's largest crocodile in captivity in 2011. The animal measures in length, weighs approximately and is estimated to be more than 110 years old. Kept at the Marineland Crocodile Park, a zoo on Green Island, Queensland, Australia, Cassius was officially recognized by Guinness in 2011, but lost the title in 2012 to Lolong, a saltwater crocodile caught in the southern Philippines. Cassius again holds the record since Lolong's death in 2013.
The largest recorded egg is from a whale shark, and was in size. Whale shark eggs typically hatch within the mother. At and up to , the ostrich egg is the largest egg of any living bird, though the extinct elephant bird and some dinosaurs laid larger eggs. The bee hummingbird produces the smallest known bird egg, which weighs half of a gram (around 0.02 oz). Some eggs laid by reptiles and most fish, amphibians, insects and other invertebrates can be even smaller.
The heaviest known cephalopod, and the largest living invertebrate, is the colossal squid. The largest recorded specimen of this species, caught in the Ross Sea in 2007, weighed . However, its beak is not the largest known from this species; even bigger colossal squid beaks have been recovered from the stomachs of sperm whales, indicating that this species can grow larger still.
An intertwined subject to the taxonomy which has been noted and studied has been the size and ontogeny (growth and development) of the individuals represented. Individuals of multiple sizes are represented in the sample, but overall they represent smaller animals than the hadrosaurs known from Asian and North American species. Despite this, a small number of individuals falling into the adult size ranges of other hadrosaurs are indicated by isolated elements, such as femurs. Multiple hypotheses have been put forward to explain this: firstly, juvenile individuals may have been the dominant life stage living in the area where the bonebed was preserved, due to ecological differences over lifespan; secondly, it's possible they represent dwarfed animals dominating the environment relative to rare a larger species; lastly, it's possible the large individuals were comparative giants of a single dwarfed species, near the extreme end of individual variation in the species. The 2015 analysis of hadrosaur dentaries from the Pyrenees found two morphotypes to be present in the bonebed, so they favored the second hypothesis. The more in-depth 2018 study used histological analysis in order to assess the age of different individuals, using tibiae. Of the several tibiae tested, four (between long) were identified as juveniles between the ages of one and three based on comparisons to tissue patterns in other ornithopods, and three more were found to likely be juveniles based on similarities to the former four. The eighth ( long) and ninth ( long) were found to belong to an early adult and subadult individual respectively. A femur was found to share subadult growth features with the subadult tibia. Three tibiae (, , and around respectively) were found to belong to adult individuals. Growth trajectory was found to be consistent between the tibiae, supporting the idea that the site represents a large variety of age stages of a single species.
The largest living chelonian is the leatherback sea turtle ("Dermochelys coriacea"), which reaches a shell length of and can reach a weight of over . Freshwater turtles are generally smaller, but with the largest species, the Asian softshell turtle "Pelochelys cantorii", a few individuals have been reported up to . This dwarfs even the better-known alligator snapping turtle, the largest chelonian in North America, which attains a shell length of up to and weighs as much as .
Giant tortoises of the genera "Geochelone", "Meiolania", and others were relatively widely distributed around the world into prehistoric times, and are known to have existed in North and South America, Australia, and Africa. They became extinct at the same time as the appearance of man, and it is assumed humans hunted them for food. The only surviving giant tortoises are on the Seychelles and Galápagos Islands and can grow to over in length, and weigh about .
Baryonyx () is a genus of theropod dinosaur which lived in the Barremian stage of the Early Cretaceous Period, about 130–125 million years ago. The first skeleton was discovered in 1983 in the Weald Clay Formation of Surrey, England, and became the holotype specimen of B. walkeri, named by palaeontologists Alan J. Charig and Angela C. Milner in 1986. The generic name, "Baryonyx", means "heavy claw" and alludes to the animal's very large claw on the first finger; the specific name, "walkeri", refers to its discoverer, amateur fossil collector William J. Walker. The holotype specimen is one of the most complete theropod skeletons from the UK (and remains the most complete spinosaurid), and its discovery attracted media attention. Specimens later discovered in other parts of the United Kingdom and Iberia have also been assigned to the genus.
"Sinosauropteryx" lived in what is now northeastern China during the early Cretaceous period. It was among the first dinosaurs discovered from the Yixian Formation in Liaoning Province, and was a member of the Jehol Biota. Well-preserved fossils of this species illustrate many aspects of its biology, such as its diet and reproduction.
In addition to Friedrich von Huene, Janensch was probably Germany's most important dinosaur specialist from the early and middle twentieth century. His most famous and significant contributions stemmed from the expedition undertaken to the Tendaguru Beds in what is now Tanzania. As leader of an expedition (together with Edwin Hennig) set up by the Museum für Naturkunde in Berlin, where he worked as a curator, Janensch helped uncover an enormous quantity of fossils of late Jurassic period dinosaurs, including several complete "Brachiosaurus" skeletons, then the largest animal ever known. During his long subsequent career (he worked in Berlin from 1914 to 1961), Janensch named several new dinosaur taxa including "Dicraeosaurus" (1914) and "Elaphrosaurus" (1920). Janensch's "Brachiosaurus" were later determined to belong to a distinct, related genus, "Giraffatitan".
The Two Medicine Dinosaur Center is a 501(c)(3) non-profit and educational institute located in Bynum, Montana that opened in 1995. It is part of the Montana Dinosaur Trail and home to a skeletal model of what is believed to be the world's largest dinosaur, a seismosaurus.
The center also houses the first baby dinosaur bones collected in North America - the original discovery reported by paleontologist John R. Horner.
While dinosaurs were ancestrally bipedal, many extinct groups included quadrupedal species, and some were able to shift between these stances. Elaborate display structures such as horns or crests are common to all dinosaur groups, and some extinct groups developed skeletal modifications such as bony armor and spines. While the dinosaurs' modern-day surviving avian lineage (birds) are generally small due to the constraints of flight, many prehistoric dinosaurs (non-avian and avian) were large-bodied—the largest sauropod dinosaurs are estimated to have reached lengths of and heights of and were the largest land animals of all time. Still, the idea that non-avian dinosaurs were uniformly gigantic is a misconception based in part on preservation bias, as large, sturdy bones are more likely to last until they are fossilized. Many dinosaurs were quite small: "Xixianykus", for example, was only about long.
The largest carnivorous dinosaur was "Spinosaurus", reaching a length of , and weighing 7–20.9 tonnes (7.7–23 short tons). Other large carnivorous theropods included "Giganotosaurus", "Carcharodontosaurus" and "Tyrannosaurus". "Therizinosaurus" and "Deinocheirus" were among the tallest of the theropods. The largest Ornithischian dinosaur was probably the hadrosaurid "Shantungosaurus" which measured and weighed about .