What is "trigonostylops"

Trigonostylops is an extinct genus of South American meridiungulatan ungulate, from the late Paleocene to early Eocene of Argentina.

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 1.50 m (5 ft) long. Teeth, primarily molars, have been found and assigned to other species.