Trigonostylops

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.

Trigonostylops Temporal range: Late Paleocene-Late Eocene (Riochican-Tinguirirican) ~58.7–33.9 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Skull restoration of Trigonostylops
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	†Astrapotheria
Family:	†Trigonostylopidae
Genus:	†Trigonostylops Ameghino 1897
Type species
Trigonostylops wortmani Ameghino 1897
Species
T. gegenbauri Roth 1899 T. wortmani Ameghino 1897

Description

Interpretation of T. wortmani

A complete skull of the type species, T. wortmani, has been found, and it has been classified as an astrapothere based on its large lower incisors.^[1]

Phylogeny

Cladogram based in the phylogenetic analysis published by Vallejo Pareja et al., 2015, showing the position of Trigonostylops:^[2]

	Eoastrapostylops
	Trigonostylops Tetragonostylops Albertogaudrya Scaglia Astraponotus Maddenia Comahuetherium Parastrapotherium Astrapotheriinae Astrapotherium Astrapothericulus Uruguaytheriinae Uruguaytherium Hilarcotherium Xenastrapotherium Granastrapotherium

Distribution

Locations of Trigonostylops fossils
Pozo Formation
Sarmiento Formation
Las Flores Formation
Not show: La Meseta Formation in Seymour Island, Antarctica

Fossils of Trigonostylops have been found in:^[3]

Paleocene

• Las Flores Formation, Argentina^[4]

Eocene

• La Meseta Formation, Antarctica^[5]
• Casamayor, Divisadero Largo, Koluel Kaike and Sarmiento Formations, Argentina^[6][7]
• Pozo Formation, Peru^[8]