Litopterna is an extinct order of South American native ungulates that lived from the Paleocene to the end of the Pleistocene-early Holocene around 63 million-12,000 years ago, and were also present in Antarctica during the Eocene. They represent the second most diverse group of South American ungulates after Notoungulata. It is divided into nine families, with Proterotheriidae and Macraucheniidae being the most diverse and last surviving families.
South American native ungulates, commonly abbreviated as SANUs, are extinct ungulate-like mammals of controversial affinities that were indigenous to South America prior to the Great American Biotic Interchange. They comprise five major groups conventionally ranked as orders—Astrapotheria, Litopterna, Notoungulata, Pyrotheria, and Xenungulata—as well as the primitive "condylarth" groups Didolodontidae and Kollpaniinae. It has been proposed that some or all of the members of this group form a clade, named Meridiungulata, though the relationships of South American ungulates remain largely unresolved. The two largest groups of South American ungulates, the notoungulates and the litopterns, were the only groups to persist beyond the mid Miocene. Only a few of the largest species of notoungulates and litopterns survived until the end-Pleistocene extinction event around 12,000 years ago where they became extinct with most other large mammals in the Americas, shortly after the first arrival of humans into the region.
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.
Seymour Island or Marambio Island, is an island in the chain of 16 major islands around the tip of the Graham Land on the Antarctic Peninsula. Graham Land is the closest part of Antarctica to South America. It lies within the section of the island chain that resides off the west side of the peninsula's northernmost tip. Within that section, it is separated from Snow Hill Island by Picnic Passage, and sits just east of the larger key, James Ross Island, and its smaller, neighboring island, Vega Island.
Astrapotheria is an extinct order of South American and Antarctic hoofed mammals that existed from the late Paleocene to the Middle Miocene, 59 to 11.8 million years ago. Astrapotheres were large, rhinoceros-like animals and have been called one of the most bizarre orders of mammals with an enigmatic evolutionary history.
Astrapotherium 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. magnus 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.
Astrapotheriidae is an extinct family of herbivorous South American land mammals that lived from the Late Eocene to the Middle Miocene 37.71 to 15.98 million years ago. The most derived of the astrapotherians, they were also the largest and most specialized mammals in the Tertiary of South America. There are two sister taxa: Eoastrapostylopidae and Trigonostylopidae.
Granastrapotherium is an extinct genus of ungulate mammals, described from remains found in rocks of the Honda Group in the Tatacoa Desert, in the Colombian departments of Huila and Tolima, at the Miocene fossil site La Venta. The only species formally recognized is Granastrapotherium snorki. Remains found in Bolivia and Peru, seem to belong to Granastrapotherium or a very similar animal.
The La Meseta Formation is a sedimentary sequence deposited during the Eocene on Seymour Island off the coast of the Antarctic Peninsula. It is noted for its fossils, which include both marine organisms and the only terrestrial vertebrate fossils from the Cenozoic of Antarctica.
Parastrapotherium is an extinct genus of South American land mammal that existed from the Late Oligocene to the Early Miocene. The genus includes some of the largest and smallest known astrapotherian, but at present no generally recognized description can adequately characterize it.
Scaglia is an extinct genus of South American astrapotherid land mammal that lived during the Eocene.
Hilarcotherium is an extinct genus of astrapotheriid mammals that lived in South America during the Middle Miocene (Laventan). The type species is H. castanedaii, found in sediments of the La Victoria Formation, part of the Honda Group in the department of Tolima in Colombia. In 2018, Carrillo et al. described a partial skull and mandible of a second species H. miyou from the Castilletes Formation in the Cocinetas Basin of northern Colombia, and estimated the body weight of the animal at 6,465 kilograms (14,253 lb).
This paleomammalogy list records new fossil mammal taxa that were described during the year 2011, as well as notes other significant paleomammalogy discoveries and events which occurred during that year.
Maddenia is an extinct genus of astrapothere, meridiungulate herbivore mammals characterised by its large tusks and the development of proboscis, endemic of South America. This genus was discovered in an outcrop near to the Lake Colhué Huapi in the place La Cantera, in the Chubut Province, in Argentina, in sediments corresponding to the Sarmiento Formation, that dates of the Late Oligocene.
Notiolofos is an extinct genus of sparnotheriodontid ungulate from the order Litopterna. The animal lived during the Eocene, in modern-day Antarctica. The genus contains two species, N. arquinotiensis, the type species, and N. regueroi.
Sparnotheriodontidae is an enigmatic extinct family of litopterns known primarily from teeth. Sparnotheriodontids are one of two South American native ungulate clades known to have reached Antarctica, the other being astrapotheres.
Notonuphar is an extinct genus of water lily in the family Nymphaeaceae. It contains a single species, Notonuphar antarctica. It is only known only from the Eocene-aged La Meseta Formation of Seymour Island, Antarctica.
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.
The Cerro Bandera Formation is a geological formation in Neuquén Province, Argentina, in northern Patagonia, which dates to the Early Miocene, around 21 to 17.5 million years ago. 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 Cerro Bandera Formation include a variety of turtles and birds, also includes many mammals such as South American native ungulates as well as armadillos, and caviomorph rodents.
Eoviscaccia is an extinct genus of chinchillid rodent that lived during the Early Oligocene (Tinguirirican) to the Early Miocene (Colhuehuapian) in what is now South America. Fossils of this genus have been found in the Cerro Bandera, Chichinales, Fray Bentos, and Sarmiento Formations of Argentina, the Salla Formation of Bolivia, and the Abanico Formation of Chile.
