Moeritherium

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Moeritherium
Temporal range: Late Eocene
Skull of Moeritherium lyonsi in the Muséum National d'Histoire Naturelle, Paris, France
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Proboscidea
Family: Moeritheriidae
C.W. Andrews, 1906
Genus: Moeritherium
C.W. Andrews, 1901
Species
  • M. andrewsi Schlosser, 1911
  • M. chehbeurameuri Delmer et al., 2006
  • M. gracile Andrews, 1902
  • M. lyonsi Andrews, 1901
  • M. trigodon Andrews, 1904

Moeritherium ('the beast from Lake Moeris') is a genus consisting of several extinct species. These prehistoric mammals are related to the elephant and, more distantly, the sea cow. They lived during the Eocene epoch.

Description[edit]

Skeleton in Japan

The Moeritherium species were pig-like animals that lived about 37-35 million years ago, and resembled modern tapirs[1] or pygmy hippopotamuses (they are not believed to be related to either of those animals, however). They were smaller than modern elephants, standing only 70 centimetres (2.3 ft) high at the shoulder and were about 3 metres (9.8 ft) long.[citation needed] They are believed[by whom?] to have wallowed in swamps and rivers, filling the ecological niche now filled by the hippopotamus. The shape of their teeth suggests that they ate soft water vegetation.

The shape of the skull suggests that Moeritherium did not have an elephant-like trunk, but it may have had a broad flexible upper lip like a tapir's for grasping aquatic vegetation. The second incisor teeth formed small tusks, although these would have looked more like the teeth of a hippo than a modern elephant.[2][3]

Discovery[edit]

Restoration from 1920
Moeritherium andrewsi skull

In 1901, Charles William Andrews described Moeritherium lyonsi from fossil remains found in the Qasr-el-Sagha formation in the Al Fayyum in Egypt. Andrews described Moeritherium gracile from fossil remains of a smaller specimen found in the same area in 1902 in a fluvio-marine formation,[4][5] that is a river estuary wetlands to brackish lagoon paleoenvironment. In 1904, the first Moeritherium trigodon fossils were discovered by Charles Andrews in the deposits of an oasis in Al Fayyum.[1][6] It is also found in other sites around North and West Africa.[7] In 1911, Max Schlosser of Munich divided Moeritherium lyonsi into two species: Moeritherium lyonsi, a large form from the Qasr-el-Sagha formation, and a new large species M. andrewsi from a fluvio-marine formation.[4][5][8] In 2006, Moeritherium chehbeurameuri has been described from fossil remains found in the early late Eocene locality of Bir El Ater, Algeria.[9]

Classification[edit]

Moeritherium is not believed to be an ancestor of modern elephants; it was a branch of the order that died out, leaving no descendants. There were several species of early elephants in existence during the Eocene, and some, such as Palaeomastodon, looked relatively similar to modern elephants. However, Moeritherium typified a branch of the family that evolved in a quite different way, having only a stubby trunk and short legs.[citation needed]

References[edit]

  1. ^ a b Koehl, D. 2006 The genus Moeritherium, ancestor of elephants. Downloaded on 6 December 2006.
  2. ^ Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 238. ISBN 1-84028-152-9. 
  3. ^ Savage, RJG, & Long, MR (1986). Mammal Evolution: an illustrated guide. New York: Facts on File. p. 147. ISBN 0-8160-1194-X. 
  4. ^ a b Matsumoto, H. 1922. Revision of Palæomastodon and Mœritherium. Palæomastodon intermedius, and Phiomia osborni, new species. American Museum Novitates. Number 51, November 21.
  5. ^ a b Matsumoto, H. 1923. A Contribution to the Knowledge of Mœritherium. Bulletin of the American Museum of Natural History ; v. 48, article 4. p. 97-140.
  6. ^ ABC Online. 2002. ABC - Science - Beasts - Moeritherium Factfile Downloaded on 6 December 2006.
  7. ^ BBC Homepage. 2006. - Science & Nature - Wildfacts - Moeritherium Downloaded on 6 December 2006.
  8. ^ Schlosser Max (1911) "Beiträge zur Kenntnis der oligozänen Landsäugetiere aus dem Fayum, Ägypten." Beiträge zur Paläontologie und Geologie Österreich-Ungarns, 24: 1–167.
  9. ^ Delmer, C., Mahboubi, M., Tabuce, R. & Tassy, P. 2006. "A new species of Moeritherium (Proboscidae, Mammalia) from the Eocene of Algeria: new perspectives on the ancestral morphotype of the genus." Palaeontology 49 (2), 421-434.