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.
Description.
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 tusks. In comparison with the later "Astrapotherium magnum", it is estimated to have been around long. Teeth, primarily molars, have been found and assigned to other species.
Phylogeny.
Cladogram based in the phylogenetic analysis published by Vallejo Pareja "et al"., 2015, showing the position of "Trigonostylops":
Distribution.
Fossils of "Trigonostylops" have been found in: