Nimravus

Nimravus
Temporal range: Early Oligocene–Early Miocene
N. brachyops jaw, University of California Museum of Paleontology
Conservation status
Fossil
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
(unranked): Feliformia
Order: Carnivora
Family: Nimravidae
Genus: Nimravus
Cope, 1879
Species
  • N. altidens
  • N. brachyops
  • N. edwardsi
  • N. gomphodus
  • N. intermedius
  • N. sectator

Nimravus is an extinct genus of the family Nimravidae, subfamily Nimravinae (false saber-toothed cat) endemic to North America during the Oligocene epoch (33.3—26.3 mya), existing for approximately 7 million years.[1]

Taxonomy

Nimravus was named by Cope (1879) [status called into question by Bryant 1996]. It is the type genus of Nimravidae, Nimravinae. It was assigned to Nimravidae by Cope (1879) and Martin (1998); and to Nimravinae by Flynn and Galiano (1982), Bryant (1991) and Hunt (1998).[2][3]

Unrelated to saber-toothed cats, they evolved a similar form through parallel evolution.

Morphology

Skull fragments

Nimravus was around 1.2 metres (4 ft) in body length. With its sleek body, it may have resembled the modern caracal, although it had a longer back and more dog-like feet with partially retractile claws. It probably hunted birds and small mammals, ambushing them like modern cats, rather than chasing them down. Nimravus competed with other false sabre-tooths such as Eusmilus.[4]

A Nimravus skull, found in North America, had been pierced in the forehead region, the hole exactly matching the dimensions of the sabre-like canine of Eusmilus. This particular individual of Nimravus apparently survived this encounter, as the wound showed signs of healing.

A single specimen was examined by M. Mendoza for body mass and was estimated to have a weight of 29.5 kg (65 lbs).[5]

Fossil distribution

Fossils were uncovered in the western U.S. from Oregon to southern California to Nebraska.

Species

N. brachyops (syn. Archaelurus debilis, Dinictis major, N. altidens, N. bumpensis, N. confertus, N. gomphodus, N. meridianus), N. sectator.

References

  1. ↑ PaleoBiology Database: Nimravus, basic info
  2. ↑ L. D. Martin. 1998. Felidae. In C. M. Janis, K. M. Scott, and L. L. Jacobs (eds.), Evolution of Tertiary Mammals of North America 1:236-242
  3. ↑ A. Berta and H. Galiano. 1983. Megantereon hesperus from the late Hemphillian of Florida with remarks on the phylogenetic relationships of machairodonts (Mammalia, Felidae, Machairodontinae). Journal of Paleontology.
  4. ↑ Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 222. ISBN 1-84028-152-9.
  5. ↑ M. Mendoza, C. M. Janis, and P. Palmqvist. 2006. Estimating the body mass of extinct ungulates: a study on the use of multiple regression. Journal of Zoology