Austral or Magallanes Basin

glacial lake in the Patagonian province of Santa Cruz, Argentina

lake in Santa Cruz Province, Argentina

lake in Capitán Prat Province, Santa Cruz Province, Argentina

Astrapotherium ("lightning beast") is an extinct genus of large astrapotherian ungulate native to South America during the early-middle Miocene. It is the best known member of the group. The type species. A. magnum have been found in the Santa Cruz Formation in Argentina. Other fossils have been found in the Deseado, Sarmiento, and Aisol Formations of Argentina and Chile (Cura-Mallín Group).

Cladosictis (meaning "branch weasel") is an extinct genus of South American metatherian from Patagonia, Argentina (Chichinales, Cerro Bandera, Sarmiento and Santa Cruz Formations) and Chile (Río Frias Formation).

lake in Argentina

Theosodon is an extinct genus of litoptern mammal from the Early to Middle Miocene of South America.

Adinotherium (meaning "not terrible beast") is an extinct genus of toxodontid, large bodied hoofed ungulates which inhabited South America during the Middle to Late Miocene, from 17.5 to 6.8 Ma and existed for approximately , Santacrucian to Huayquerian in the South American land mammal ages (SALMA). Fossils of Adinotherium have been found in the Santa Cruz and Ituzaingó Formations of Argentina and the Chucal and Río Frías Formations of Chile.

Homalodotherium is an extinct genus of South American native ungulates in the order Notoungulata. Fossils of Homalodotherium have been found in the Middle Miocene (Friasian in the SALMA classification) 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 (H. cunnin

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.

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.

Diadiaphorus is an extinct genus of litoptern mammal from the Miocene of Argentina (Ituzaingó, Pinturas, Chiquimil and Santa Cruz Formations) and Bolivia (Nazareno Formation), South America.

Nesodon ("island tooth") is a genus of Miocene mammal belonging to the extinct order Notoungulata which inhabited southern South America during the Late Oligocene to Miocene living from 29.0 to 16.3 Ma and existed for approximately . It had a relatively large size, weighing up to 554 kg (1221 lbs) and reaching 1.5 m in height.

genus of mammals

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.

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.

Prepotherium is an extinct genus of megatheriid ground sloths that lived during the Miocene period. Fossils of Prepotherium have been found in the Collón Curá and Santa Cruz Formations of Argentina.

Tetramerorhinus is an extinct genus of proterotheriid litoptern that lived during the Early and Middle Miocene in what is now Argentina and Peru.

Magallanodon is a genus of large mammal from the extinct group Gondwanatheria. It contains a single species, Magallanodon baikashkenke. The species is the first Mesozoic mammal known from Chile, and is Late Cretaceous in age. It is known from individual teeth found in a quarry in the Río de Las Chinas Valley and La Anita Farm located in the Magallanes Basin in Patagonia. The fossils come from the Dorotea Formation and Chorrillo Formation, which is Late Campanian to Early Maastrichtian in age. It was more recently estimated to weigh ~10.34 kg.

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

geological formation in Argentina

geological formation

Orretherium (meaning "Five teeth beast"; in part from the Aonikenk language) is a genus of mesungulatid mammal that lived in South America (Chile) during the Late Cretaceous period in what is now the Dorotea Formation. It is estimated to have weighed ~1.3kg.