The South American land mammal ages (SALMA) establish a geologic timescale for prehistoric South American fauna beginning 64.5 Ma during the Paleocene and continuing through to the Late Pleistocene. These periods are referred to as ages, stages, or intervals and were established using geographic place names where fossil materials where obtained.
The Casamayoran age is a period of geologic time within the Early Eocene epoch of the Paleogene, used more specifically within the South American land mammal age (SALMA) classification. It follows the Itaboraian and precedes the Mustersan age.
The Santacrucian age is a period of geologic time within the Early Miocene epoch of the Neogene, used more specifically with SALMA classification in South America. It follows the Colhuehuapian and precedes the Friasian age.
The Chasicoan age is a period of geologic time from 10–9 Ma within the Late Miocene epoch of the Neogene, used more specifically within the SALMA classification in South America. It follows the Mayoan and precedes the Huayquerian age.
The Huayquerian age is a period of geologic time within the Late Miocene epoch of the Neogene, used more specifically within the SALMA classification. It follows the Mayoan and precedes the Montehermosan age.
Proterotheriidae is an extinct family of fossil ungulates from the Cenozoic era that displays toe reduction. Despite resembling primitive, small horses, they were only distantly related to them, and instead belonged to the native South American ungulate order Litopterna.
Neolicaphrium is an extinct genus of ungulate mammal belonging to the extinct order Litopterna. This animal lived from the Late Pliocene (Chapadmalalan) to the Late Pleistocene (Lujanian) in southern South America, being the last survivor of the family Proterotheriidae.
The Colorado Basin is a sedimentary basin located in northeastern Patagonia. The basin stretches across an area of approximately 180,000 square kilometres (69,000 sq mi), of which 37,000 square kilometres (14,000 sq mi) onshore in the southern Buenos Aires Province and the easternmost Río Negro Province extending offshore in the South Atlantic Ocean.
The Cerro Azul Formation, in the Buenos Aires Province also described as Epecuén Formation, is a geological formation of Late Miocene age in the Colorado Basin of the Buenos Aires and La Pampa Provinces in northeastern Argentina.
Cullinia is an extinct genus of litoptern, an order of South American native ungulates that included horse-like and camel-like animals such as Macrauchenia. It is only known from fragmentary remains. Cullinia levis is known from Chasicoan remains found in the Arroyo Chasicó Formation of Argentina, and remains from the Brazilian state of Acre and the Huayquerian Ituzaingó Formation have been assigned to Cullinia sp..
Proterotherium is an extinct genus of litoptern mammal of the family Proterotheriidae that lived during the Late Miocene of Argentina and Chile. Fossils of this genus have been found in the Ituzaingó Formation of Argentina, and the Galera Formation of Chile.
Deuterotherium is an extinct genus of South American native ungulates, which lived during the Deseadan age of the Oligocene in what is now Argentina. Its type species is Deuterotherium distichum. It was named by Florentino Ameghino in 1895. The holotype of Deuterotherium distichum is a calcaneum. It was formerly identified as a proterotheriid litoptern. In 1999, Shockey argued Deuterotherium was certainly not a litoptern and interpreted it as a notohippid notoungulate. In research by Soria posthumously published in 2001, Soria considered Deuterotherium a nomen dubium.
Polymorphis is an extinct genus of litopterns belonging to the family Macraucheniidae. It lived during the Middle Eocene of Argentina.
Brachytherium is an extinct genus of proterotheriid mammal from the Late Miocene to Late Pliocene of Argentina. It is represented by the type and only species B. cuspidatum, a taxon named in 1883 by Ameghino for a partial mandible with teeth. Though it was considered a dubious taxon at times, Brachytherium was revised as valid by Schmidt in 2015, who also synonymized the species Proterotherium gradatum and Lophogonodon paranensis, expanding the material known, all of which is from the Ituzaingó Formation. Some material previously referred to Brachytherium has been given the new name Neobrachytherium.
Neobrachytherium is an extinct genus of proterotheriid mammal from the Late Miocene of Argentina and Uruguay. It is represented by multiple species, including the type N. intermedium, originally named in 1891 by Moreno and Mercerat as a species of Licaphrium, N. morenoi, originally named in 1914 by Rovereto as a species of Brachytherium, and N. ameghinoi and N. ullumense, named in 2001 by Soria, who reclassified all the species in the new genus Neobrachytherium. The various species are known from cranial and dental material from the Corral Quemado, Loma de las Tapias and Ituzaingó Formations. Neobrachytherium may be closely related to Thoatherium, Diadiaphorus and Thoatheriopsis.
Protheosodon is an extinct genus of proterotheriid litoptern. It lived from the Late Oligocene to the Early Miocene in what is now Argentina and Colombia.
Xesmodon is an extinct genus of mammal. It lived from the Middle to the Late Eocene, in what is today South America.
Tetramerorhinus is an extinct genus of proterotheriid litoptern. It lived during the Early Miocene in what is now Argentina and Peru.
Anisolophus is an extinct genus of proterotheriid from the Early to Middle Miocene of Argentina. The genus was named by Burmeister in 1885 to accommodate the species Anchitherium australe, which they had named earlier in 1879. Soria then referred the species Licaphrium floweri and Anisolophus minisculus to the genus, making Licaphrium, named in 1887 by Florentino Ameghino, a junior synonym of the genus. Both A. australis and A. floweri are known from the Santacrucian age Santa Cruz Formation, while A. minisculus is known from the Collón Curá Formation.
Paramacrauchenia is an extinct genus of proterotheriid litopterns from the Early Miocene of what is now Chile. Its fossils have been found in the Santa Cruz Formation of Chile.
