Peltephilus, the horned armadillo, is an extinct genus of armadillo xenarthran mammals that first inhabited Argentina during the Oligocene epoch, and became extinct in the Miocene epoch. Notably, the scutes on its head were so developed that they formed horns. Aside from the horned gophers of North America, it is the only known fossorial horned mammal. P. ferox had skull about 11.7 centimetres (4.6 in), and estimated body mass is around 11.07 kilograms (24.4 lb).
Hapalops is an extinct genus of ground sloth from the Early to Late Miocene of Brazil, Bolivia, Colombia, and Argentina in South America.
Theosodon is an extinct genus of litoptern mammal from the Early to Middle Miocene of South America.
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.
Homalodotherium is an extinct genus of South American native ungulates in the order Notoungulata. Fossils of Homalodotherium have been found in the Middle Miocene Santa Cruz Formation of Argentina and the Río Frías Formation of Chile. The first specimen, a partial skull, was discovered by Robert Holiver Cunningham while on an expedition to Patagonia. By the time it had arrived in England, it was degraded to the point where only a few elements remained. Regardless, in 1870, it was given its genus name by Thomas Henry Huxley, and its species name by William Henry Flower. The name was misspelled repeatedly over the years, leading to the erection of the family Homalodontotheriidae to include it, though this has since been amended to Homalodotheriidae. Since, then four more species of Homalodotherium have been named.
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.
The Neoepiblemidae are an extinct family of hystricognath rodents from South America. The genera Dabbenea and Perumys are now included in Phoberomys. The delineation between Neoepiblemidae and Dinomyidae has historically been unclear, with some genera having varying taxonomic placement. A 2017 study found Phoberomys to be part of the group, while Eusigmomys was found to be part of the Dinomyidae.
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 Deseadan age is a period of geologic time within the Oligocene epoch of the Paleogene to the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification of South America. It follows the Tinguirirican and precedes the Colhuehuapian 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 Agua de la Piedra Formation is a Late Oligocene geologic formation of the Malargüe Group that crops out in the southernmost Precordillera and northernmost Neuquén Basin in southern Mendoza Province, Argentina.
Ethegotherium is an extinct genus of Notoungulates, belonging to the suborder Typotheria. It lived from the Lower to the Middle Miocene, and its fossilized remains were discovered in South America. It might be a synonym of the genus Prohegetotherium.
Prepoplanops is an extinct genus of ground sloth of the family Megatheriidae. It lived in the Miocene around 18 to 16 million years ago of what is now Argentina. The only known species is Prepoplanops boleadorensis.
Interatheriinae is an extinct subfamily of interatheriids that consisted of notoungulates dating from the Early Eocene to the Early Pliocene. The subfamily includes the genera Archaeophylus, Argyrohyrax, Boleatherium, Brucemacfaddenia, Caenophilus, Choichephilum, Cochilius, Eopachyrucos, Federicoanaya, Interatherium, Juchuysillu, Miocochilius, Neoicochilus, Patriarchus, Proargyrohyrax, Progaleopithecus, Protypotherium, and Santiagorothia. They were small to medium sized interatheres, and when compared to the other subfamily, Notopithecinae, interatheriines are found to occupy an advanced, derived position in the family.
Hegetotheriopsis is an extinct genus of hegetotheriid notoungulate. It lived from the Late Oligocene to the Early Miocene, and its fossilized remains are found in Argentina.
The Sarmiento Formation, in older literature described as the Casamayor Formation, is a geological formation in Chubut Province, Argentina, in central Patagonia, which spans around 30 million years from the mid-Eocene to the early Miocene. It predominantly consists of pyroclastic deposits, which were deposited in a semi-arid environment. It is divided up into a number of members. The diverse fauna of the Sarmiento Formation, including a variety of birds, crocodilians, turtles and snakes, also includes many mammals such as South American native ungulates as well as armadillos, and caviomorph rodents.
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.
Federicoanaya is an extinct genus of interatheriine notoungulates that lived during the Late Oligocene in what is now Bolivia. Fossils of this genus have been found in the Salla Formation of Bolivia.
The Santa Cruz Formation is a geological formation in the Magallanes/Austral Basin in southern Patagonia in Argentina and adjacent areas of Chile. It dates to the late Early Miocene epoch, and is contemporaneous with the eponymous Santacrucian age of the SALMA timescale. The Santa Cruz Formation is known for its abundance of vertebrate fossils, including South American native ungulates, as well as rodents, xenarthrans, and metatherians.
Eucholoeops is a genus of megalonychid ground sloth that lived in southernmost Argentina. Fossils have been recovered from the lower Santa Cruz Formation of Patagonia, which has been dated to the Early Miocene. The type species, E. ingens, was named by Florentino Ameghino in 1887 based on skull fossils, encased in geological matrix, from the collection of his brother. These remains were never removed from the matrix, and have since been lost. Florentino Ameghino went on to name five more species if Eucholoeops, and another palaeontologist, Aldice Mercerat, named two more. All are now believed to represent the same taxon as E. ingens, and the lost type specimen has been replaced with a neotype lower jaw.
