Simpsonotus

Simpsonotus
Temporal range: Mid-Late Paleocene (Peligran)
~60–56 Ma
↓
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: †Notoungulata
Family: †Henricosborniidae
Genus: †Simpsonotus
Pascual et al. 1978
Type species
†Simpsonotus praecursor
Pascual et al. 1978
Species
  • Simpsonotus major Pascual et al. 1978
  • Simpsonotus praecursor (type) Pascual et al. 1978

Simpsonotus is an extinct genus of notoungulate mammals in the family Henricosborniidae from the Middle to Late Paleocene of South America. Fossils of the genus have been found in the Mealla Formation, a fluvial and lacustrine sedimentary unit of the Salta Basin in northwestern Argentina.[1][2] The genus name honors paleontologist George Gaylord Simpson.

Description

Simpsonotus had a skull similar to Notostylops, but with a shorter and rounder face. The genus contains two species; the type species S. praecursor,[3] and the double-sized S. major,[4] both described by Pascual et al. in 1978.[5]

Age

The Mealla Formation was initially described as Riochican in the South American land mammal age classification, and later as Itaboraian, but after the redefinition of the Itaboraí Formation to Early Eocene, the Mealla Formation is Peligran in age.

References

  1. ^ Sánchez & Marquillas, 2009, p.389
  2. ^ Narváez, 2009, p.172
  3. ^ S. praecursor at Fossilworks.org
  4. ^ S. major at Fossilworks.org
  5. ^ Pascual et al., 1978

Bibliography

  • Narváez, Paula Liliana (2009), Palinoestratigrafía, paleoambientes y cambios climáticos durante el Cretácico final y Paleógeno de la Cuenca del Grupo Salta, República Argentina (PhD thesis) (PDF), Universidad Nacional de Salta, pp. 1–229, retrieved 2020-06-13
  • Sánchez, María Cristina; Marquillas, Rosa A. (2010), "Facies y ambientes del Grupo Salta (Cretácico-Paleógeno) en Tumbaya, Quebrada de Humahuaca, Provincia de Jujuy" (PDF), Revista de la Asociación Geológica Argentina, 67: 383–391, retrieved 2020-06-13
  • Pascual, R.; Vucetich, M.G.; Fernández, J. (1978), "Los primeros mamiferos (notoungulata, henricosborniidae) de la Formacion Mealla (Grupo Salta, subgrupo Santa Barbara) : sus implicancias filogeneticas, taxonomicas y cronologicas", Ameghiniana, 15: 366–390