WAmerhippus is an extinct subgenus of Equus which includes several species of horses that lived in South America. They were one of two groups of equines in South America alongside Hippidion. Fossils have been recovered from the Tarija Formation of Bolivia, the Serranía del Perijá in Venezuela, the Chiu-Chiu Formation of Chile, the Sabana Formation of the Bogotá savanna in Colombia, and from various locations in Ecuador. The subgenus lived from 2.588 to 0.012 Mya. It measured roughly 1.5 m (4.9 ft) tall and weighed approximately 400 kg (880 lb). While they have formerly been referred to as belonging to 5 separate species, this has been revised down into three, and more recently a single, morphologically variable species Equus neogeus. Equus first appeared in South America during the late Early Pleistocene around 1 Ma. A 2008 study of mitochondrial DNA fragments of a specimen of E. neogeus found it to be nested within mitochondrial lineages of E. caballus. A close relationship to caballine horses was also supported by a 2019 morphological analysis study.
WArctotherium is an extinct genus of Pleistocene South American short-faced bears within Ursidae. Their ancestors migrated from North America to South America during the Great American Interchange, following the formation of the Isthmus of Panama during the late Pliocene. The oldest dated confirmed remains are those of A. angustidens from Buenos Aires, Argentina, dating to the Ensenadan epoch, 1.76 to 0.98 Ma old, within the Early to Middle Pleistocene, with a tooth possibly belonging to Arctotherium dating about 2.588 Mya. They are genetically closer to the spectacled bear, than to Arctodus of North America, implying the two extinct forms evolved large size in a convergent manner, perhaps to facilitate dominating other carnivores in the competition for the biggest carcasses. The northernmost species, A. wingei, known from Venezuela in South America, apparently invaded Central America and reached as far north as the Yucatán.
WCuvieronius is an extinct New World genus of gomphotheres and is named after the French naturalist Georges Cuvier. Alive, specimens typically stood about 2.3 m (7.5 ft) tall at the shoulder, weighed about 3.5 t and would have superficially resembled a modern elephant with spiral-shaped tusks.
WGlossotherium was a genus of ground sloth. It was a heavily built animal with a length of about 4 metres (13 ft) snout to tail-tip, a weight estimated at 1,000 kg (2,200 lb), and could potentially assume a slight bipedal stance.
WGlyptodon was a genus of large, heavily armored mammals of the subfamily Glyptodontinae – relatives of armadillos – that lived during the Pleistocene epoch. It was roughly the same size and weight as a Volkswagen Beetle. With its rounded, bony shell and squat limbs, it superficially resembled a turtle, and the much earlier dinosaurian ankylosaur – providing an example of the convergent evolution of unrelated lineages into similar forms. In 2016 an analysis of Doedicurus mtDNA found it was, in fact, nested within the modern armadillos as the sister group of a clade consisting of Chlamyphorinae and Tolypeutinae. For this reason, glyptodonts and all armadillos but Dasypus were relocated to a new family, Chlamyphoridae, and glyptodonts were demoted from the former family Glyptodontidae to a subfamily.
WGlyptotherium is an extinct genus of glyptodont, a group of extinct mammals related to the armadillos living from the Middle to Late Pleistocene, approximately 1.8 million to 12,000 years ago (AEO). The genus is considered an example of North American megafauna, of which most have become extinct. Glyptotherium may have been wiped out by changing climate or human interference.
WThis is a list of gomphothere fossils found in South America. Gomphotheres were elephant-like mammals that lived from the Middle Miocene to the Holocene.
WHippidion is an extinct genus of horse that lived in South America from the Late Pliocene to the end of the Late Pleistocene (Lujanian), between two million and 11,000 years ago. They were one of two lineages of equines native to South America during the Pleistocene epoch alongside those of the Equus subgenus Amerhippus.
WHolmesina is a genus of pampathere, an extinct group of armadillo-like creatures that were distantly related to extant armadillos. Like armadillos, and unlike the other extinct branch of megafaunal cingulates, the glyptodonts, the shell was made up of flexible plates which allowed the animal to move more easily. Holmesina species were herbivores that grazed on coarse vegetation; armadillos are mostly insectivorous or omnivorous.
WMacrauchenia was a large, long-necked and long-limbed, three-toed native South American mammal in the order Litopterna. The genus gives its name to its family, the Macraucheniidae or "robust litopterns". Like other litopterns, it is not closely related to any living mammal, being most closely related to the group containing horses, rhinos and tapirs, from which litopterns diverged approximately 66 million years ago. The oldest fossils in the genus date to the late Miocene, around seven million years ago, and M. patachonica disappears from the fossil record during the late Pleistocene, around 20,000-10,000 years ago. M. patachonica is one of the last and best known member of the family and is known primarily from the Luján Formation in Argentina, but is known from localities across southern South America. Another genus of macraucheniid Xenorhinotherium was present in northeast Brazil and Venezuela during the Late Pleistocene. The type specimen was discovered by Charles Darwin during the voyage of the Beagle. In life, Macrauchenia may have resembled a humpless camel, though the two taxa are not closely related. It fed on plants in a variety of environments across what is now South America. Among the species described, M. patachonica and M. ullomensis are considered valid; M. boliviensis is considered a nomen dubium; and M. antiqua has been moved to the genus Promacrauchenia.
WMixotoxodon is an extinct genus of notoungulate of the family Toxodontidae inhabiting South America, Central America and parts of southern North America during the Pleistocene, from 1,800,000—12,000 years ago.
WXenorhinotherium is an extinct genus of macraucheniids, closely related to Macrauchenia of Patagonia. The type species is X. bahiense.