Trigonostylops Explained

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 incisors.^[1]

Phylogeny

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

Distribution

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]

References

Bibliography

• Antoine . P.O. . Marivaux . L. . Croft . Darin A. Croft . D.A. . Billet . G. . Ganerod . M. . Jaramillo . Carlos Jaramillo (geologist) . C. . Martin . T. . Orliac . M. . Tejada . J. . A. J. . Altamirano . F. . Duranthon . G. . Fanjat . S. . Rousse . R. . Salas Gismondi . 2011 . Middle Eocene rodents from Peruvian Amazonia reveal the pattern and timing of caviomorph origins and biogeography . . 279 . 1732 . 1319–1326 . 10.1098/rspb.2011.1732 . 21993503 . 26368929 . 2019-02-14. 3282368 .
• Cifelli . R . 1985 . Biostratigraphy of the Casamayoran, Early Eocene of Patagonia . . 2820 . 1–26 . 2019-02-14.
• Dzik . J. . Gaździcki . A. . 2001 . The Eocene expansion of nautilids to high latitudes . . 172 . 3–4 . 297–312 . 10.1016/S0031-0182(01)00304-2 . 2001PPP...172..297D . 2019-02-14.
• Goin . F.J. . Candela . A.M. . Abello . M.A. . Oliveira . E.V. . 2009 . Earliest South American paucituberculatans and their significance in the understanding of 'pseudodiprotodont' marsupial radiations . . 155 . 4 . 867–884 . 10.1111/j.1096-3642.2008.00471.x . 84131123 . 2019-02-14. free .
• Vallejo Pareja . M.C. . Carrillo . J.D. . Moreno Bernal . J.W. . Pardo Jaramillo . M. . Rodríguez González . D.F. . Muñoz Duran . J. . 2015 . Hilarcotherium castanedaii, gen. et sp. nov., a new Miocene astrapothere (Mammalia, Astrapotheriidae) from the Upper Magdalena Valley, Colombia . Zurich Open Repository and Archive, University of Zurich . 35 . 2 . 1–14 . 10.1080/02724634.2014.903960 . 2015JVPal..35E3960V . 130728894 . 2019-02-14.
• Vera . B . 2012 . Revisión del género Transpithecus Ameghino, 1901 (Notoungulata, Interatheriidae) del Eoceno medio de Patagonia, Argentina . . 49 . 60–74 . 10.5710/AMGH.v49i1(361) . 130102948 . 2019-02-14.

Notes and References

1. Book: Palmer, D.. 1999 . The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals . Marshall Editions . London . 249 . 978-1-84028-152-1.
2. Vallejo Pareja et al., 2015
3. http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=43458 Trigonostylops
4. Goin et al., 2009
5. Dzik & Gaździcki, 2001
6. Vera, 2012
7. Cifelli, 29185, p.5
8. Antoine et al., 2011