Instruct: Given a question, retrieve passages that can help answer the question.
Query: What did Machairodontinae primarily prey on?
On occasion, the bone of a fossilised predator is preserved well enough to retain recognizable proteins that belong to the species it consumed when alive. Stable isotope analysis of these proteins has shown that "Smilodon" preyed mainly on bison and horses, and occasionally ground sloths and mammoths, while "Homotherium" often preyed on young mammoths and other grazers such as pronghorn antelope and bighorn sheep when mammoths were not available.
A fully-grown "Smilodon" weighed approximately and had a short tail, powerful legs, and a large head. The cats have two huge canine teeth, about long, that are used to kill prey by suffocation. The jaws could open to about 120 degrees in order to use these fangs to deadly effect. They would die out due to climate change.
Smilodon is a genus of the extinct machairodont subfamily of the felids. It is one of the most famous prehistoric mammals, and the best known saber-toothed cat. Although commonly known as the saber-toothed tiger, it was not closely related to the tiger or other modern cats. "Smilodon" lived in the Americas during the Pleistocene epoch (2.5 mya–10,000 years ago). The genus was named in 1842, based on fossils from Brazil. Three species are recognized today: S. gracilis, S. fatalis, and S. populator. The two latter species were probably descended from "S. gracilis", which itself probably evolved from "Megantereon". The hundreds of individuals obtained from the La Brea Tar Pits in Los Angeles constitute the largest collection of "Smilodon" fossils.
Now recognised as a member of the family Spinosauridae, "Baryonyx" affinities were obscure when it was discovered. Some researchers have suggested that "Suchosaurus cultridens" is a senior synonym (being an older name), and that "Suchomimus tenerensis" belongs in the same genus; subsequent authors have kept them separate. "Baryonyx" was the first theropod dinosaur demonstrated to have been piscivorous (fish-eating), as evidenced by fish scales in the stomach region of the holotype specimen. It may also have been an active predator of larger prey and a scavenger, since it also contained bones of a juvenile "Iguanodon". The creature would have caught and processed its prey primarily with its forelimbs and large claws. "Baryonyx" may have had semiaquatic habits, and coexisted with other theropod, ornithopod, and sauropod dinosaurs, as well as pterosaurs, crocodiles, turtles and fishes, in a fluvial environment.
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.
Though similar to "Palaeopropithecus", "Archaeoindris" was significantly larger and more robust. "Archaeoindris" was one of the largest primates to ever evolve, and was the largest-known strepsirrhine primate, weighing an estimated . It was roughly the size of an adult male gorilla, which was first noted by Lamberton.
Puncture marks made by teeth on several "Eutrephoceras" fossils (such as "E. campbelli", of the Trent River Formation in Vancouver) are cited as evidence of mososaur predation on this genus.
"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.
Mosasaurs (from Latin "Mosa" meaning the 'Meuse river', and Greek σαύρος "sauros" meaning 'lizard') are an extinct group of large marine reptiles containing 38 genera in total. Their first fossil remains were discovered in a limestone quarry at Maastricht on the Meuse in 1764. Mosasaurs probably evolved from an extinct group of aquatic lizards known as aigialosaurs in the Early Cretaceous. During the last 20 million years of the Cretaceous period (Turonian-Maastrichtian ages), with the extinction of the ichthyosaurs and pliosaurs, mosasaurs became the dominant marine predators. They became extinct as a result of the K-Pg event at the end of the Cretaceous period, about 66 million years ago.
The same specimen of "S. prima" which had preserve a lizard in its stomach contents (NIGP 127587) also had several small eggs in its abdomen. Two eggs were preserved just in front of and above the pubic boot, and several more may lie underneath them on the slab. It is unlikely that they were eaten by the animal, as they are in the wrong part of the body cavity for the egg shells to have remained intact. It is more likely that they are unlaid eggs produced by the animal itself, proving the specimen to be a female. Each egg measured long by wide. The presence of two developed eggs suggests that "Sinosauropteryx" had dual oviducts and laid eggs in pairs, like other theropods.
Platecarpus ("flat wrist") is an extinct genus of aquatic lizards belonging to the mosasaur family, living around 84–81 million years ago during the middle Santonian to early Campanian, of the Late Cretaceous period. Fossils have been found in the United States and a possible specimen in Belgium and Africa. A well-preserved specimen of "Platecarpus" shows that it fed on moderate-sized fish, and it has been hypothesized to have fed on squid, and ammonites as well. Like other mosasaurs, it was initially thought to have swum in an eel-like fashion, although another study suggests that it swam more like modern sharks. An exceptionally well-preserved specimen of "P. tympaniticus" known as LACM 128319 shows skin impressions, pigments around the nostrils, bronchial tubes, and the presence of a high-profile tail fluke, showing that it and other mosasaurs did not necessarily have an eel-like swimming method, but were more powerful, fast swimmers. It is held in the Natural History Museum of Los Angeles County.
Recent molecular phylogenetic studies suggest that most placental orders diverged late in the Cretaceous period, about 100 to 85 million years ago, but that modern families first appeared later, in the late Eocene and early Miocene epochs of the Cenozoic period. Fossil-based analyses, on the contrary, limit the placentals to the Cenozoic. Many Cretaceous fossil sites contain well-preserved lizards, salamanders, birds, and mammals, but not the modern forms of mammals. It is likely that they simply did not exist, and that the molecular clock runs fast during major evolutionary radiations. On the other hand, there is fossil evidence from of hoofed mammals that may be ancestors of modern ungulates.
The horse adapted to survive in areas of wide-open terrain with sparse vegetation, surviving in an ecosystem where other large grazing animals, especially ruminants, could not. Horses and other equids are odd-toed ungulates of the order Perissodactyla, a group of mammals that was dominant during the Tertiary period. In the past, this order contained 14 families, but only three—Equidae (the horse and related species), Tapiridae (the tapir), and Rhinocerotidae (the rhinoceroses)—have survived to the present day.
The elephants comprise three living species and are the largest living land animals.Sirenia is an order of fully aquatic, herbivorous mammals that inhabit rivers, estuaries, coastal marine waters, swamps, and marine wetlands. All four species are endangered.The treeshrews are small mammals native to the tropical forests of Southeast Asia. Although called treeshrews, they are not true shrews and are not all arboreal.The two species of colugos make up the order Dermoptera. They are arboreal gliding mammals found in Southeast Asia.The order Primates contains humans and their closest relatives: lemurs, lorisoids, monkeys, and apes.Rodents make up the largest order of mammals, with over 40 percent of mammalian species. They have two incisors in the upper and lower jaw which grow continually and must be keep short by gnawing. Most rodents are small though the capybara can weigh up to 45 kg (100 lb).
Their diet includes the fruit and seeds of local cactus plants, as well as beans of the mesquite plant. They do not only eat vegetation, and also consume insects, small rodents and carrion. They have a variety of predators including the bobcat, coyotes, as well as local snakes and domestic animals such as dogs and cats.
Hurum, Zhe-Xi Luo, and Kielan-Jaworowska suggested in 2006 that the spurs on the ankles of Mesozoic mammals (such as "Catopsbaatar") were homologous with those of monotremes, and were a basal (or "primitive") feature lost by later therian mammals. The male platypus uses the spur to deliver venom from a gland, but it is unknown if the extinct groups were venomous as well. Mesozoic mammals were mostly small (with exceptions such as the fox-sized "Repenomamus") and, although they were too small to be prey for large theropod dinosaurs, smaller theropods, large lizards, crocodiles, and birds could have fed on them. For example, mammal jaws have been found in the abdomen of a specimen of the small theropod "Sinosauropteryx"; the jaws belonged to "Zhangheotherium", which also had spurs, and the multituberculate "Sinobaatar". Since dinosaurs dominated Earth during the Mesozoic, this period has been called the "dark ages" of mammalian history. The spur, which would have been more effective if venomous, was probably used as a defensive weapon by small, early mammals. It could also have been used during intraspecific competition or predation.
The pelvic bones of "Catopsbaatar" specimen PM120/107 may not have been fused because fusion occurred late in development, because it was a sexually dimorphic feature only occurring in males (unfused pelvic bones might have enabled expansion of the birth canal in females), or pelvic fusion may be a taxonomic difference between "Catopsbaatar" and other multituberculates. Unlike with other mammals, the pelvis of multituberculates was very narrow; in other genera where the pelvis is known, each half of the pubis and ischium were fused together, forming a keel. The length and rigidity of the keel indicate that the pelvis could not have spread during birth. Because there would be little space for the passage of an egg (egg-laying monotremes have wide ischial archs), Kielan-Jaworowska suggested in 1979 that multituberculates were viviparous (gave live birth) and that the newborns were extremely small—similar to those of marsupials.
Several large (~3 meters) and advanced members of this group ("Ctenospondylus", "Sphenacodon", "Secodontosaurus" and "Dimetrodon") are distinguished by a tall sail along the back, made up of elongated vertebral neural spines, which in life must have been covered with skin and blood vessels, and presumably functioned as a thermoregulatory device. However, possession of a sail does not appear to have been essential for these animals. For example, there is the case in which one genus ("Sphenacodon" – fossils known from New Mexico) lacks a sail, while a very similar and closely related genus ("Dimetrodon" – fossils known from Texas) has one. During the Permian, these two regions were separated by a narrow sea-way, but it is not clear why one geographically isolated group should evolve a sail, but the other group not.
Dimetrodon ( or , meaning "two measures of teeth") is an extinct genus of synapsids that lived during the Cisuralian (Early Permian), around 295–272 million years ago (Ma). It is a member of the family Sphenacodontidae. The most prominent feature of "Dimetrodon" is the large neural spine sail on its back formed by elongated spines extending from the vertebrae. It walked on four legs and had a tall, curved skull with large teeth of different sizes set along the jaws. Most fossils have been found in the southwestern United States, the majority coming from a geological deposit called the Red Beds of Texas and Oklahoma. More recently, fossils have been found in Germany. Over a dozen species have been named since the genus was first described in 1878.
Hair, structurally similar to that of modern mammals and associated with bones of the Mongolian multituberculate "Lambdopsalis", has been identified in coprolites (fossilised feces) of carnivorous mammals from the Palaeocene Epoch. This indicates that multituberculates had hair for insulation, similar to modern mammals (and possibly fossil mammals), a feature probably related to homeothermy (warm-bloodedness).
Nile crocodiles "(Crocodylus niloticus)" the largest living reptile seen in river banks and ponds in the two protected parks, the dwarf caiman, smaller and docile species of chameleons in 100 colour variations. 
Tortoises are: leopard tortoise "(Stigmochelys pardalis)", several species of terrapin and turtles – out of eight species of marine turtles four are found in Benin coast, namely, the green sea turtle "(Chelonia mydas)", olive ridley sea turtle "(Lepidochelys olivacea)" and leatherback sea turtle ("Dermochelys coriacea"). The indigenous hawksbill sea turtle "(Eretmochelys imbricata)" is the source of traditional tortoiseshell). 
Lizards found are harmless and of two types, the water and savanna monitors – "Varanus niloticus" and "Varanus exanthematicus" – both are predatory species; house gecko "(Hemidactylus mabouia)", a translucent white lizard; agama species in large size of varied mixed colours and the skinks.
During the 1830s, Danish naturalist Peter Wilhelm Lund and his assistants collected fossils in the calcareous caves near the small town of Lagoa Santa, Minas Gerais, Brazil. Among the thousands of fossils found, he recognized a few isolated cheek teeth as belonging to a hyena, which he named "Hyaena neogaea" in 1839. After more material was found (including canine teeth and foot bones), Lund concluded the fossils instead belonged to a distinct genus of felid, though transitional to the hyenas. He stated it would have matched the largest modern predators in size, and was more robust than any modern cat. Lund originally wanted to name the new genus "Hyaenodon", but realizing this had recently become preoccupied by another prehistoric predator, he instead named it "Smilodon populator" in 1842. He explained the Ancient Greek meaning of "Smilodon" as ("smilē"), a scalpel or two-edged knife, and "οδόντος" ("odontús"), tooth. This has also been translated as "tooth shaped like double-edged knife". He explained the species name "populator" as "the destroyer", which has also been translated as "he who brings devastation". By 1846, Lund had acquired nearly every part of the skeleton (from different individuals), and more specimens were found in neighboring countries by other collectors in the following years. Though some later authors used Lund's original species name "neogaea" instead of "populator", it is now considered an invalid "nomen nudum" ("naked name"), as it was not accompanied with a proper description and no type specimens were designated. Some South American specimens have been referred to other genera, subgenera, species, and subspecies, such as "Smilodontidion riggii", "Smilodon" ("Prosmilodon") "ensenadensis", and "S. bonaeriensis", but these are now thought to be junior synonyms of "S. populator".
The name 'saber-toothed tigers' is misleading. Machairodonts were not in the same subfamily as tigers, there is no evidence that they had tiger-like coat patterns, and this broad group of animals did not all live or hunt in the same manner as the modern tiger. DNA analysis published in 2005 confirmed and clarified cladistic analysis in showing that the Machairodontinae diverged early from the ancestors of modern cats and are not closely related to any living feline species.
A more common and widely accepted view of machairodont hunting is the throat-shearing bite. Modern cats use a throat clamp, a bite positioned around the upper section of the throat, to suffocate the prey by compressing the windpipe. Their canines serve to puncture the skin and mostly allow a better grip, and do not do any significant damage to the prey. Machairodonts, alternatively, would have caused damage if they used the same technique as their modern relatives.
The most studied section of the machairodont group is the skull, and specifically the teeth. With a large range of genera, good fossil representation, comparable modern relatives, diversity within the group, and a good understanding of the ecosystems inhabited, the machairodont subfamily provides one of the best means of research for the analysis of hypercarnivores, specialization, and the relationships between predator and prey.
Modern cats, and presumably the basal genera of all cats, such as "Pseudaelurus" and "Proailurus", use the throat clamp as a common method of dispatching prey. The suffocation would inhibit sound from the panicked prey, a method used by modern cheetahs and leopards. The wound from the canines and the lack of air would then kill the prey animal.