Typotheres

Typotheria is a suborder of the extinct South American native ungulate order Notoungulata. A majority of the members of this clade were superficially similar to lagomorphs and rodents, though this is due to convergence. The clade was named after Typotherium, a synonym of Mesotherium.

Hegetotheriidae is an extinct family of notoungulate mammals known from the Oligocene through the Pliocene of South America. The family underwent many sequential radiation events throughout the Cenozoic, which led to Hegetotheriids being among the most diverse of the Typotheria.

Interatheriidae is an extinct family of notoungulate mammals from South America. Interatheriids are known from the Middle Eocene (Mustersan) to the Early Pleistocene (Uquian). These animals were principally small-sized, occupying a habitat like hares, marmots and viscachas. The majority were very small, like rodents.

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.

Pachyrukhos is an extinct genus of hegetotheriid notoungulate from the Early to Middle Miocene (Colhuehuapian-Friasian in the SALMA classification) of Argentina and Chile. Fossils of this genus have been found in the Collón Curá, Sarmiento and Santa Cruz Formations of Argentina and the Río Frías Formation of Chile.

Archaeopithecidae is an extinct family comprising two genera of notoungulate mammals, Teratopithecus and Archaeopithecus, both known from the Eocene of Argentina.

Mesotheriidae ("Middle Beasts") is an extinct family of notoungulate mammals known from the Oligocene through the Pleistocene of South America. Mesotheriids were small to medium-sized herbivorous mammals adapted for digging.

Mesotherium ("middle beast") is an extinct genus of mesotheriid, a long-lasting family of superficially rodent-like, burrowing notoungulates from South America. It is one of the youngest notoungulates, spanning the Early-Middle Pleistocene, and is the last known member of Typotheria. It was first named by Étienne Serres in 1857, though initially lacked a type species. Another genus name Typotherium, was put forward by Auguste Bravard, and three species were included: however, the name Typotherium was not applied to any particular specimens, and is thus invalid. A type species for Mesotherium,

Interatherium is an extinct genus of interatheriid notoungulate that lived from the Early to Middle Miocene (Colhuehuapian-Mayoan). Fossils of this genus have been found in the Santa Cruz, Collón Curá and Sarmiento Formations in Argentina.

Archaeohyracidae is an extinct family of notoungulate mammals known from the Paleocene through the Oligocene of South America. First named in 1897, it is now thought to be paraphyletic, rather than a genuine group of closely related animals with a single, unique, ancestor.

Hegetotherium is a small to middle-sized extinct genus of mammals, ranging from the size of rabbit (about 20-30 cm/12-16") to a beaver (about 3 ft/1 m) from the Early to Middle Miocene (Colhuehuapian-Colloncuran in the SALMA classification), through Pliocene sites of South America. Fossils of this genus have been found in the Cerro Bandera, Cerro Boleadoras, Chichinales, Collón Curá, Santa Cruz and Sarmiento Formations of Argentina, the Nazareno Formation of Bolivia, and the Galera and Río Frías Formations of Chile.

Trachytherus is an extinct genus of mesotheriid notoungulate that lived from the Late Oligocene to the Early Miocene in what is now South America.

Campanorco is an extinct genus of notoungulate mammal from the Middle Eocene Lumbrera Formation, Argentina, South America and the only member of the family Campanorcidae. It contains only a single species, Campanorco inauguralis.

Oldfieldthomasia is an extinct genus of notoungulate, probably related to the suborder Typotheria. It lived during the Middle Eocene, in what is today 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.

Allalmeia was a small notoungulate mammal of around 3 kilograms. It lived in Mendoza Province, Argentina (Divisadero Largo Formation) during the Late Eocene. Allalmeia belonged to the Oldfieldthomasiidae family within the suborder Typotheria.

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.

Hemihegetotherium is an extinct genus of hegetotheriid notoungulate that lived from the Middle to the Late Miocene of what is now Argentina.

Paginula is an extinct genus of oldfieldthomasiid notoungulate. It lived during the Eocene in what is now Argentina.

Miocochilius is an extinct genus of small notoungulate mammals (typotheres) native to South America. The genus lived during the Middle Miocene epoch (Laventan in the SALMA classification). 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.

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.

Oldfieldthomasiidae is an extinct family of notoungulate mammals known from the Late Paleocene to Late Eocene of South America. The family was classified by George Gaylord Simpson in 1945 and a synonym is Acoelodidae, defined by Florentino Ameghino in 1901.

Cochilius is an extinct genus of interatheriid notoungulate that lived between the Late Oligocene and the lower Miocene in what is now Argentina.