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


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]


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]


  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[edit]