Trigonostylops

Trigonostylops Temporal range: Late Paleocene–Early Eocene PreЄ Є O S D C P T J K Pg N
Trigonostylops
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Superorder:	†Meridiungulata
Order:	†Astrapotheria
Family:	†Trigonostylopidae
Genus:	†Trigonostylops Ameghino 1897
Type species
Trigonostylops wortmani Ameghino, 1897

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.^[1] 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:^[2]

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

References

1. Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 249. ISBN 1-84028-152-9.
2. Vallejo-Pareja, M. C.; Carrillo, J. D.; Moreno-Bernal, J. W.; Pardo-Jaramillo, M.; Rodriguez-Gonzalez, D. F.; Muñoz-Duran, J. (2015). "Hilarcotherium castanedaii, gen. et sp. nov., a new Miocene astrapothere (Mammalia, Astrapotheriidae) from the Upper Magdalena Valley, Colombia". Journal of Vertebrate Paleontology. 35 (2): e903960. doi:10.1080/02724634.2014.903960. (subscription required (help)).