Heptodon

Heptodon
Temporal range: Early Eocene
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Perissodactyla
Superfamily: Tapiroidea
Family: Helaletidae
Genus: Heptodon
Cope, 1882
Species
  • H. calciculus
  • H. posticus

Heptodon is an extinct genus of tapir-type herbivore of the family Helaletidae endemic to North America during the Eocene epoch. It lived from 55.4—48.6 mya, existing for approximately 6.8 million years.[1]

Taxonomy

Heptodon was named by Cope (1882). It was considered paraphyletic by Colbert (2005). It was assigned to Helaletinae by Radinsky (1966); to Ceratomorpha by Cope (1882) and Colbert and Schoch (1998); to Heptodontidae by Holbrook (1999);[2] and to Tapiroidea by Colbert (2005). M. W. Colbert. 2005.[3]

Morphology

Heptodon was about 1 metre (3.3 ft) in length, and closely resembled modern tapirs. The shape of the skull suggests that it probably lacked the characteristic tapir trunk. Instead it probably had a slightly elongated, fleshy upper lip, like its relative Helatetes.[4]

A single specimen was examined by M. Mendoza, C. M. Janis, and P. Palmqvist for body mass. It was estimated to have a weight of 15.5 kg (34 lb).[5]

References

  1. PaleoBiology Database: Heptodon, basic info
  2. L. T. Holbrook. 1999. The Phylogeny and classification of tapiromorph perissodactyls (Mammalia) . Cladistics 15(3):331-350
  3. M. W. Colbert and R. M. Schoch. 1998. Tapiroidea and other moropomorphs. In C. M. Janis, K. M. Scott, and L. L. Jacobs (eds.), Evolution of Tertiary mammals of North America 569-582
  4. Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 261. 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 270

See also

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