Notostylops

Notostylops Temporal range: Early-Late Eocene (Casamayoran-Divisaderan) ~48.6–37.2  Ma PreꞒ Ꞓ O S D C P T J K Pg N
Notostylops
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	† Notoungulata
Family:	† Notostylopidae
Genus:	† Notostylops Ameghino, 1897
Species
N. murinus(type species) Ameghino, 1897 N. appressus(Ameghino, 1902) N. pendens(Ameghino, 1901) N. pigafettai Simpson, 1948
Synonyms
Anastylops Ameghino, 1897 Catastylops Ameghino, 1901 Entelostylops Ameghino, 1901 Eostylops Ameghino, 1901 Isostylops Ameghino, 1902 Pliostylops Ameghino, 1901

Notostylops ("south pillar face") is a genus of extinct South American notoungulates from Eocene Argentina. Fossils of the genus have been found in the Sarmiento, Casamayor, Andesitas Huancache and Koluel Kaike Formations. ^[1]

• 
  Size comparison of Notostylops murinus with a human.
• 
  Life reconstruction.

Description

Notostylops was a very generalised animal, very similar to the first eutherians and ungulates. It would have superficially resembled a marmot or a wombat and is suspected to have browsed on low-growing plants. It was probably adapted to a fairly wide range of ecological niches, but its robustness indicates it had some digging adaptations. ^{[2] [3]} Its tall skull housed rodent-like incisor teeth. Notostylops incisors lacked complex, decussating enamel prisms, instead possessing radial enamel. ^[4] Notostylops was about 75 centimetres (30 in) long. ^[5]

References

1. Notostylops at Fossilworks.org
2. Croft, Darin. Horned Armadillos and Rafting Monkeys. Indiana University Press.
3. Lorente, Malena; Gelfo, Javier; Lopez, Guillermo (2018). "First skeleton of the notoungulate mammal Notostylops murinus and palaeobiology of Eocene Notostylopidae". Lethaia . 52 (2): 244–259. doi:10.1111/let.12310. S2CID   135127572.
4. Filippo, Andréa; Kalthoff, Daniela C.; Billet, Guillaume; Gomes Rodrigues, Helder (13 March 2019). "Evolutionary and Functional Implications of Incisor Enamel Microstructure Diversity in Notoungulata (Placentalia, Mammalia)". Journal of Mammalian Evolution . 27 (2): 211–236. doi:10.1007/s10914-019-09462-z. ISSN   1064-7554 . Retrieved 31 October 2025– via Springer Nature Link.
5. Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 250. ISBN   978-1-84028-152-1.

• Media related to Notostylops at Wikimedia Commons