Mustersan

Niolamia is an extinct genus of South American meiolaniid turtle with a long and complex history. Like its relatives, Niolamia was a robust and heavily armored terrestrial turtle with large, horn like scales covering its head and a tail encased by rings of bone. This heavily armored build may have served the animal during intraspecific combat during courtship, though such encounters likely did not involve the horns and frill, which are thought to serve more of a display function. Scans of the skull reveal that Niolamia likely had a great sense of smell but only low frequency hearing, indicatin

Notostylops ("south pillar face") is a genus of extinct South American notoungulates from Eocene Argentina. Fossils of the genus have been found in the Sarmiento, Casamayor, Andesitas Huancache and Koluel Kaike Formations. Image:Notostylopss.png|Size comparison of Notostylops murinus with a human. Image:Notostylops murinus Wikipedia Juandertal.jpg|Life reconstruction.

Trigonostylops is an extinct genus of South American meridiungulatan ungulate, from the Late Paleocene to Late Eocene (Itaboraian to Tinguirirican in the SALMA classification) of South America (Argentina and Peru) and Antarctica (Seymour Island). It is the only member of the family Trigonostylopidae.

Thomashuxleya is an extinct genus of notoungulate mammal, named after famous 19th-century biologist Thomas Huxley.

Proborhyaenidae is an extinct family of metatherian mammals of the order Sparassodonta, which lived in South America from the Eocene (Mustersan) until the Oligocene (Deseadan). Sometimes it has been included as a subfamily of their relatives, the borhyaenids (as Proborhyaeninae). The largest species, Proborhyaena gigantea, is estimated to be about the size of a spectacled bear, with its skull reaching in length, and body mass estimates up to approximately , making the proborhyaenids some of the largest known metatherians. Proborhyaenid remains have been found in western Bolivia, Uruguay, south

Madtsoia is an extinct genus of madtsoiid snakes. It is known from the Eocene of Argentina (M. bai), the Paleocene of Brazil (M. camposi), the Late Cretaceous (Maastrichtian) of India (M. pisdurensis), and the Late Cretaceous (Maastrichtian) of Madagascar (M. madagascariensis). The type species (M. bai) was the largest with an estimated length of , and the other three species were smaller. A long M. madagascariensis would have weighed , but an isolated specimen suggests that this species reached in maximum length. Juvenile Madtsoia madagascariensis may have eaten a wide array of small vertebra

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.

Pseudoglyptodon is a genus of extinct sloths from South America. The type species is Pseudoglyptodon sallaensis.

Henricosbornia is an extinct genus of henricosborniid notoungulate that lived from the Late Paleocene to the Middle Eocene of what is now Argentina and Brazil.

Astraponotus is an extinct genus of astrapotheriids. It lived during the Middle-Late Eocene (in the Mustersan and Tinguirirican of the South American land mammal ages (SALMA), 48-33.9 million years ago) and its fossil remains have been found in the Sarmiento Formation of Argentina, South America.