Taxa named by George Gaylord Simpson

Teilhardina (, ) is an extinct marmoset-like omomyid primate that lived in Europe, North America and Asia during the Early Eocene epoch, about 56-47 million years ago. The paleontologist George Gaylord Simpson named it after the French paleontologist, Jesuit and philosopher Teilhard de Chardin.

Holmesina is an extinct genus of pampathere, a group of armadillo-like xenarthrans that were distantly related to extant armadillos. Like armadillos, and unlike the other extinct branch of megafaunal cingulates the glyptodonts, the shell was made up of flexible plates which allowed the animal to move more easily. thumb|left|Holmesina occidentalis thumb|left|Life reconstruction of Holmesina floridanus and size comparation Holmesina individuals were much larger than any modern armadillo: They could reach a length of , and a weight of , while the modern giant armadillo does not attain more than

Carpolestes (from Ancient Greek καρπός (karpós), meaning "fruit", and λῃστής (lēistḗs), meaning "robber", and thus, "fruit robber") is a genus of extinct primate-like mammals from the late Paleocene of North America. It first existed around 58 million years ago. The three species of Carpolestes appear to form a lineage, with the earliest occurring species, C. dubius, ancestral to the type species, C. nigridens, which, in turn, was ancestral to the most recently occurring species, C. simpsoni.

Notioprogonia is a suborder of the extinct mammalian order Notoungulata and includes two families, Henricosborniidae and Notostylopidae.

Scarrittia is an extinct genus of hoofed mammal of the family Leontiniidae, native to South America during the Late Oligocene epoch (Deseadan in the SALMA classification).

Carodnia is an extinct genus of South American ungulate known from the Early Eocene of Brazil, Argentina, and Peru. Carodnia is placed in the order Xenungulata together with Etayoa and Notoetayoa.

species of mammal (fossil)

REDIRECT Dugongidae

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

Sebecus (meaning "Sobek" in Latin) is an extinct genus of sebecid crocodylomorph from Paleogene period of South America. Like other sebecosuchians, it was entirely terrestrial and carnivorous. The genus is currently represented by two species, the type S. icaeorhinus and S. ayrampu. Several other species have been referred to Sebecus, but were later reclassified as their own genera.

Saigini is a tribe of artiodactyl mammals of the Bovidae family, subfamily Antilopinae, comprising two species of medium-sized antelopes that inhabit the Eurasian steppes.

Trioracodon is an extinct genus of Late Jurassic to Early Cretaceous eutriconodont mammal found in North America and the British Isles. It was named in 1928.

Paromomyidae is a family of mammals that may include the earliest primates, or taxa closely related to them.

The Amphidontidae are a family of extinct mammals from the Early Jurassic to the Early Cretaceous, belonging to the eutriconodonts. It contains most of the species previously belonged to Amphilestidae.

Eocaiman is an extinct genus of caiman containing species living from the Early Paleocene to Miocene in what is now Argentina (Salamanca and Sarmiento Formations), Itaboraí Formation of Brazil and Colombia (Honda Group). Eocaiman contains three described species: E. cavernensis, E. palaeocenicus, and E. itaboraiensis, and is typically recovered as one of the more basal members of Caimaninae. Notocaiman was synonymized with Eocaiman paleocenicus in 2022.

Amphidon is an extinct genus of Late Jurassic mammal from the Morrison Formation. It is present in stratigraphic zone five. Two species have been named in the genus: Amphidon superstes and Amphidon aequicrurius, by Simpson in 1925.

Aploconodon is an extinct genus of Late Jurassic mammals belonging to the family Amphidontidae. It contains one species, A. comoensis.

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.