Smilodectes

Smilodectes
Temporal range: 55–50 Ma
Early Eocene
Smilodectes skeleton.
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Family: Nothactidae
Subfamily: Nothactinae
Genus: Smilodectes
Wortman, 1903
Species
  • Smilodectes gracilis (Marsh, 1871a)
  • Smilodectes mcgrewi Gingerich, 1979
  • Smilodectes gingerichi (Beard, 1988)

Smilodectes is an extinct genus of primate that lived in Wyoming. It possesses a post-orbital bar and grasping thumbs and toes. Smilodectes has a small cranium size and the foramen magnum was located at the back of the skull, on the occipatal bone.

It appears during the Eocene epoch, and is thought to be related to lemurs.

Contents

Named species

There are three named species: Smilodectes gracilis, Smilodectes gingerichi and Smilodectes mcgrewi.

Smilodectes gracilis

Smilodectes gracilis was an adapiformes primate from the early Eocene, some 55 million years ago. S. gracilis was found on the land mass of North America and based on its dental morphology, S. gracilis was a folivore.[1]

S. gracilis had a dental formula of Upper: 2.1.4.3, lower: 2.1.4.3 and had a relatively short snout, with rounded frontal bone as compared to other nothactines.[1] This species lacked symphyseal fusion[2] and this species of primate had comparatively reduced olfactory bulbs and a more expanded visual cortex.[1] This suggests that S. gracilis was a diurnal species.[1] S. gracilis had a cranial capacity of 9.5 cc.[2] It is thought that S. gracilis had an average body mass of around 2.1 kilograms.[1] Based upon its postcranial skeleton, S. gracilis was a vertical clinger and leaper.[2]

Smilodectes gingerichi

Smilodectes mcgrewi

References

  1. ^ a b c d e Fleagle, J. G. (1988). Primate Adaptation and Evolution. New York: Academic Press. 
  2. ^ a b c Martin, R. D. (1990). Primate Origins and Evolution: A Phylogenetic Reconstruction. Princeton, New Jersey: Princeton University Press. 

External links