Notoungulata is an extinct order of ungulates that inhabited South America from the early Paleocene to the end of the Pleistocene, living from approximately 61 million to 11,000 years ago. Notoungulates were morphologically diverse, with forms resembling animals as disparate as rabbits and rhinoceroses. Notoungulata are the largest group of South American native ungulates, with over 150 genera in 14 families having been described, divided into two major subgroupings, Typotheria and Toxodontia. Notoungulates first diversified during the Eocene. Their diversity declined from the late Neogene onwards, with only the large toxodontids persisting until the end of the Pleistocene, perishing as part of the Late Pleistocene megafauna extinctions along with most other large mammals across the Americas. Collagen sequence analysis suggests that notoungulates are closely related to litopterns, another group of South American ungulates, and their closest living relatives being perissodactyls, including rhinoceroses, tapirs and equines as part of the clade Panperissodactyla. However their relationships to other South American ungulates are uncertain. Several groups of notoungulates separately evolved ever-growing cheek teeth.
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.
Interatherium is an extinct genus of interatheriid notoungulate from the Early to Middle Miocene (Colhuehuapian-Mayoan). Fossils have been found in the Santa Cruz, Collón Curá and Sarmiento Formations in Argentina.
Miocochilius is an extinct genus of small notoungulate mammals (typotheres) native to South America. The genus lived during the Middle Miocene epoch. The genus contains two described species, the type species M. anomopodus described in 1953 by Ruben Arthur Stirton and M. federicoi, described and included in the genus by Darin A. Croft.
Prosotherium is an extinct genus of late Oligocene hegetotheriid notoungulate. It has been found in two Argentinian fossil formations, ie, the Sarmiento Formation in Chubut Province, and the Agua de la Piedra Formation in Mendoza Province.
Propachyrucos is an extinct genus of late Oligocene hegetotheriid notoungulate. It is known from a few mandibular fragments from the Sarmiento Formation, Chubut Province, Argentina.
Juchuysillu is an extinct genus of interatheriid notoungulate. It lived from the Early to the Middle Miocene, and its fossils have been found in Bolivia.
Argyrohyrax is an extinct genus of interatheriid notoungulate that lived during the Late Oligocene, of what is now Argentina and Bolivia.
Patriarchus is an extinct genus of interatheriid notoungulates that lived during the Early Miocene in what is now Argentina. Fossils of this genus have been found in the Santa Cruz Formation of Argentina.
Santiagorothia is an extinct genus of interatheriid notoungulate. It lived during the Early Oligocene, and its fossils were discovered in Argentina and Chile.
Cochilius is an extinct genus of interatheriid notoungulate that lived between the Late Oligocene and the lower Miocene in what is now Argentina.
Notopithecus is an extinct genus of Notoungulate, belonging to the suborder Typotheria. It lived from the Middle to the Late Eocene and its fossilized remains were discovered in South America.
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.
Boleatherium is an extinct genus of interatheriid notoungulate that lived from the Early to Middle Miocene of what is now Argentina. Fossils of this genus have been found in the Cerro Boleadoras Formation, the formation which this genus was named after.
Eopachyrucos is an extinct genus of interatheriid notoungulates that lived from the Middle Eocene to the Late Oligocene of Argentina and Uruguay. Fossils of this genus have been found in the Sarmiento Formation of Argentina and the Fray Bentos Formation of Uruguay.
Moqueguahippus is an extinct genus of notohippid notoungulates that lived during the Late Oligocene of what is now Peru. Fossils of this genus have been found in the Moquegua Formation of Peru, which it was named after.
Progaleopithecus is an extinct genus of interatheriid notoungulate that lived during the Late Oligocene of Argentina. Fossils of this genus have been found in the Agua de la Piedra, Deseado, and Sarmiento Formations of Argentina.
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.
Brucemacfaddenia 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 Fray Bentos Formation is a Deseadan geologic formation of the Paysandú Group in Uruguay and portions of Argentina, corresponding to the Paraná Basin. It is composed of calcareous sandstones and siltstones with a pinkish-orange coloration. It outcrops in southwestern Uruguay, the central and southeastern part of the province of Corrientes and northeast Entre Ríos.
