Caviidae, the cavy family, is composed of rodents native to South America and includes the domestic guinea pig, wild cavies, and the largest living rodent, the capybara. They are found across South America in open areas from moist savanna to thorn forests or scrub desert. This family of rodents has fewer members than most other rodent families, with 19 species in 6 genera in 3 subfamilies.
The family Caenolestidae contains the seven surviving species of shrew opossum: small, shrew-like marsupials that are confined to the Andes mountains of South America. The order is thought to have diverged from the ancestral marsupial line very early. They were once included in the superorder but it is now known that Ameridelphia is paraphyletic, having given rise to Australidelphia, and thus could be considered an evolutionary grade. Genetic studies indicate that they are the second most basal order of marsupials, after the didelphimorphs. As recently as 20 million years ago, at least seven genera were in South America. Today, just three genera remain. They live in inaccessible forest and grassland regions of the High Andes.
Maras, subfamily Dolichotinae, are a group of rodents in the family Caviidae. These large relatives of guinea pigs are common in the Patagonian steppes of Argentina, but also live in Paraguay and elsewhere in South America. There are two extant species, the Patagonian mara of the genus Dolichotis and the Chacoan mara of the genus Pediolagus. Traditionally this species was also thought to belong to Dolichotis; however, a 2020 study by the American Society of Mammalogists found significant difference between the two mara species to warrant resurrecting the genus Pediolagus for it. Several extinct genera are also known.
The Chacoan mara or Chacoan cavy is a relatively large South American rodent of the cavy family. They are a close relative of the better known Patagonian mara. The Chacoan mara is the sole member of the genus Pediolagus.
The Patagonian mara is a relatively large rodent in the mara genus Dolichotis. It is also known as the Patagonian cavy or Patagonian hare. This herbivorous, somewhat rabbit-like animal is found in open and semiopen habitats in Argentina, including large parts of Patagonia. A population has also been recorded in the northern United Arab Emirates, possibly as a result of escaped pets or captive animals. It is monogamous, but often breeds in warrens shared by several pairs.
Pyrotherium is an extinct genus of South American ungulate, of the order Pyrotheria, that lived in what is now Argentina and Bolivia, during the Late Oligocene. It was named Pyrotherium because the first specimens were excavated from an ancient volcanic ash deposit. Fossils of the genus have been found in the Deseado and Sarmiento Formations of Argentina and the Salla Formation of Bolivia.
Protypotherium is an extinct genus of notoungulate mammals native to South America during the Oligocene and Miocene epochs. A number of closely related animals date back further, to the Eocene. Fossils of Protypotherium have been found in the Deseadan Fray Bentos Formation of Uruguay, Muyu Huasi and Nazareno Formations of Bolivia, Cura-Mallín and Río Frías Formations of Chile, and Santa Cruz, Salicas, Ituzaingó, Aisol, Cerro Azul, Cerro Bandera, Cerro Boleadoras, Chichinales, Sarmiento and Collón Curá Formations of Argentina.
Rhynchippus is an extinct genus of notoungulate mammals from the Late Oligocene of South America. The genus was first described by Florentino Ameghino in 1897 and the type species is R. equinus, with lectotype MACN A 52–31. Fossils of Rhynchippus have been found in the Agua de la Piedra and Sarmiento Formations of Argentina, the Salla and Petaca Formations of Bolivia, the Tremembé Formation of Brazil, and the Moquegua Formation of Peru.
Cramauchenia is an extinct genus of litoptern South American ungulate. Cramauchenia was named by Florentino Ameghino. The name has no literal translation. Instead, it is an anagram of the name of a related genus Macrauchenia. This genus was initially discovered in the Sarmiento Formation in the Chubut Province, in Argentina, and later it was found in the Chichinales Formation in the Río Negro Province and the Cerro Bandera Formation in Neuquén, also in Argentina, in sediments assigned to the SALMA Colhuehuapian, as well as the Agua de la Piedra Formation in Mendoza, in sediments dated to the Deseadan. In 1981 Soria made C. insolita a junior synonym of C. normalis. A specimen of C. normalis was described in 2010 from Cabeza Blanca in the Sarmiento Formation, in sediments assigned to the Deseadan SALMA.
Palaeospheniscus bergi is a species of the extinct penguin genus Palaeospheniscus. It stood about 60 to 75 centimetres high in life, or somewhat smaller on average than the extant African penguin.
Scalabrinitherium is an extinct genus of mammals of the family Macraucheniidae. Fossils of this animal were found among the fossils of prehistoric xenarthrans in the Ituzaingó Formation of Argentina.
Hoplophorus is an extinct genus of glyptodont, a subfamily of armadillos. The only confidently known species was H. euphractus, found in Pleistocene deposits in Brazil, though fossils possibly from another species are known from Bolivia.
Patagornis is a genus of extinct flightless predatory birds of the family Phorusrhacidae. Known as "terror birds", these lived in what is now Argentina during the Early and Middle Miocene; the Santa Cruz Formation in Patagonia contains numerous specimens. Patagornis was an agile, medium sized Patagornithine and was likely a pursuit predator.
Cruschedula is an enigmatic bird genus considered to be nomen dubium which consists of the single species Cruschedula revola.
Neosclerocalyptus was an extinct genus of glyptodont that lived during the Pliocene, Pleistocene, and Holocene of Southern South America, mostly Argentina. It was small compared to many Glyptodonts at only around 2 meters long and 360 kilograms.
Kelenkura is an extinct genus of heavily armored mammals belonging to the subfamily Glyptodontinae, from the family Chlamyphoridae that contain most of the modern armadillos. It was a medium-sized South American animal, distantly related to Doedicurus. Fossils of this genus were recovered in the Arroyo Chasicó Formation and in the Loma de Las Tapias Formation of Argentina in rocks dating back to the Late Miocene epoch.
Tremacyllus is an extinct genus of hegetotheriids. It lived from the Late Miocene to the Late Pleistocene and its fossilized remains were discovered in South America.
Archaeopithecus is an extinct genus of Notoungulate, belonging to the suborder Typotheria. It lived during the Middle Eocene, in what is today Argentina.
Perimys is an extinct genus of neoepiblemid rodent that lived from the Early to Late Miocene in what is now South America. Fossils have been found in the Cerro Bandera, Cerro Boleadoras, Ituzaingó, Santa Cruz, and Sarmiento Formations of Argentina, and the Galera, Santa Cruz and Río Frías Formations of Chile.
Eoviscaccia is an extinct genus of chinchillid rodent that lived during the Early Oligocene (Tinguirirican) to the Early Miocene (Colhuehuapian) in what is now South America. Fossils of this genus have been found in the Cerro Bandera, Chichinales, Fray Bentos, and Sarmiento Formations of Argentina, the Salla Formation of Bolivia, and the Abanico Formation of Chile.
