Equidae is the taxonomic family of horses and related animals, including the extant horses, asses, and zebras, and many other species known only from fossils. The family evolved around 50 million years ago from a small, multi-toed ungulate into larger, single-toed animals. All extant species are in the genus Equus, which originated in North America. Equidae belongs to the order Perissodactyla, which includes the extant tapirs and rhinoceros, and several extinct families.
Perissodactyla is an order of ungulates. The order includes about 17 living species divided into three families: Equidae, Rhinocerotidae (rhinoceroses), and Tapiridae (tapirs). They typically have reduced the weight-bearing toes to three or one of the five original toes, though tapirs retain four toes on their front feet. The nonweight-bearing toes are either present, absent, vestigial, or positioned posteriorly. By contrast, artiodactyls bear most of their weight equally on four or two of the five toes: their third and fourth toes. Another difference between the two is that perissodactyls digest plant cellulose in their intestines, rather than in one or more stomach chambers as artiodactyls, with the exception of Suina, do.
Smilodon is a genus of felids belonging to the extinct subfamily Machairodontinae. It is one of the best known saber-toothed predators and prehistoric mammals. 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. The genus was named in 1842 based on fossils from Brazil; the generic name means "scalpel" or "two-edged knife" combined with "tooth". 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 specimens obtained from the La Brea Tar Pits in Los Angeles constitute the largest collection of Smilodon fossils.
Tapirs are large, herbivorous mammals belonging to the family Tapiridae. They are similar in shape to a pig, with a short, prehensile nose trunk. Tapirs inhabit jungle and forest regions of South and Central America and Southeast Asia. They are one of three extant branches of Perissodactyla, alongside equines and rhinoceroses. Only a single genus, Tapirus, is currently extant. Tapirs migrated into South America during the Pleistocene epoch from North America after the formation of the Isthmus of Panama as part of the Great American Interchange. Tapirs were formerly present across North America, but became extinct in the region at the end of the Late Pleistocene, around 12,000 years ago.
The South American tapir, also commonly called the Brazilian tapir, the Amazonian tapir, the maned tapir, the lowland tapir, anta, and la sachavaca, is one of the four recognized species in the tapir family. It is the largest surviving native terrestrial mammal in the Amazon.
Tapirus is a genus of tapir which contains the living tapir species. The Malayan tapir is usually included in Tapirus as well, although some authorities have moved it into its own genus, Acrocodia.
Litopterna is an extinct order of South American native ungulates that lived from the Paleocene to the end of the Pleistocene-early Holocene around 63 million-12,000 years ago, and were also present in Antarctica during the Eocene. They represent the second most diverse group of South American ungulates after Notoungulata. It is divided into nine families, with Proterotheriidae and Macraucheniidae being the most diverse and last surviving families.
Chalicotheriidae is an extinct family of herbivorous, odd-toed ungulate (perissodactyl) mammals that lived in North America, Eurasia, and Africa from the Middle Eocene until the Early Pleistocene, existing from 48.6 to 1.806 mya. They are often called chalicotheres, a term which is also applied to the broader grouping of Chalicotherioidea. They are noted for their unusual morphology compared to other ungulates, such as their elongated clawed forelimbs. They are thought to have been browsers.
Macrauchenia is an extinct genus of large ungulate native to South America from the late Pliocene to the end of the Pleistocene. It is a member of the extinct order Litopterna, a group of South American native ungulates distinct from the two orders which contain all living ungulates which had been present in South America since the early Cenozoic, over 60 million years ago, prior to the arrival of living ungulates in South America around 2.5 million years ago as part of the Great American Interchange. The bodyform of Macrauchenia has been described as similar to a camel, being one of the largest known litopterns, with an estimated body mass of around 1 tonne. The genus gives its name to its family, Macraucheniidae, which like Macrauchenia typically had long necks and three toed feet, as well a retracted nasal region, which in Macrauchenia manifests as the nasal opening being on the top of the skull behind the eye sockets. This has historically been argued to correspond to the presence of a tapir-like proboscis, but some recent authors suggest a moose-like prehensile lip or a saiga antelope-like nose to filter dust are more likely.
Teratornis was a genus of huge North American birds of prey—the best-known of the teratorns—of which, two species are known to have existed: Teratornis merriami and Teratornis woodburnensis. A large number of fossil and subfossil bones, representing more than 100 individuals, have been found in locations in California, Oregon, southern Nevada, Arizona, and Florida, though most are from the Californian La Brea Tar Pits. All remains except one Early Pleistocene partial skeleton from the Leisey Shell Pit near Charlotte Harbor, Florida date from the Late Pleistocene, with the youngest remains dating from the Pleistocene–Holocene boundary.
The giant tapir is an extinct species of tapir that lived in southern China, Vietnam and Laos, with reports suggesting it also lived in Taiwan, Java, and potentially Borneo. The species has been recorded from Middle and Late Pleistocene. There is only weak evidence for a Holocene survival. Tapirus augustus was larger than any living tapir, with an estimated weight of about 623 kilograms (1,373 lb). The species was also placed in its own genus of Megatapirus, however, it is now conventionally placed within Tapirus.
The Inglis quarry or Inglis quarry sites 1A and 1C are assemblages of vertebrate fossils dating from the Pleistocene ~1.8 Mya—300,000 years ago, located in the phosphate quarries near the town of Inglis, Citrus County, northern Florida.
Brontotheriidae is a family of extinct mammals belonging to the order Perissodactyla, the order that includes horses, rhinoceroses, and tapirs. Superficially, they looked rather like rhinos with some developing bony nose horns, and were some of the earliest mammals to have evolved large body sizes. They lived around 56–34 million years ago, until the very close of the Eocene. Brontotheres had a Holarctic distribution, with the exception of Western Europe: they occupied North America, Asia, and Eastern Europe. They were the first fossilized mammals to be discovered west of the Mississippi, and were first discovered in South Dakota.
Tapirus merriami, commonly called Merriam's tapir, is an extinct species of tapir which inhabited North America during the Pleistocene.
Homogalax is an extinct genus of tapir-like odd-toed ungulate. It was described on the basis of several fossil finds from the northwest of the United States, whereby the majority of the remains come from the state of Wyoming. The finds date to the Lower Eocene between 56 and 48 million years ago. In general, Homogalax was very small, only reaching the weight of today's peccaries, with a maximum of 15 kg. Phylogenetic analysis suggests the genus to be a basal member of the clade that includes today's rhinoceros and tapirs. In contrast to these, Homogalax was adapted to fast locomotion.
Tapirus haysii is an extinct species of tapir that inhabited North America during the early to middle Pleistocene Epoch (~2.5–1 Ma). The fossil remains of two juvenile T. haysii were collected in Hillsborough County, Florida on August 31, 1963. It was the second largest North American tapir; the first being T. merriami.
Tapirus veroensis is an extinct tapir species that lived in the area of the modern eastern and southern United States during the Pleistocene epoch (Irvingtonian-Rancholabrean). Tapirus veronensis is thought to have gone extinct around 11,000 years ago.
Tapirus lundeliusi is an extinct species of tapir that lived in Florida in the early Pleistocene. It was similar in size and shape to the still-living mountain tapir, with an estimated weight of 203 kg
Tapirus mesopotamicus is an extinct species of tapir that lived in South America during the Pleistocene. It is considered a possible ancestor of all extant South American tapirs.
Tapirus rondoniensis is an extinct species of large sized tapir that lived in northwestern parts of Brazil during the Pleistocene. Fossils of the species were found in the Río Madeira Formation of Rondônia, after which the species is named.
