Nesodon
Extinct genus of notoungulates
Nesodon ("island tooth") is a genus of Miocene mammal belonging to the extinct order Notoungulata which inhabited southern South America during the Late Oligocene to Miocene living from 29.0 to 16.3 Ma and existed for approximately 12.7 million years. It had a relatively large size, weighing up to 554 kg (1221 lbs) and reaching 1.5 m in height.
01Taxonomy
Nesodon was named by Owen (1846). It was assigned to Toxodontidae by Carroll (1988). It was an early member of the family Toxodontidae, which included the well-known Pleistocene genus Toxodon. Like almost all toxodontids, Nesodon was endemic to South America. In particular, fossils of Nesodon are known from late early Miocene (Santacrucian SALMA) deposits of Argentina and Chile.
Three species of Nesodon are recognized including a larger species, N. imbricatus, and a smaller species, N. conspurcatus. A poorly known and possibly invalid third species, N. cornutus, was similar to N. imbricatus but may have had a small horn on its head. All species of Nesodon were larger than species of the contemporary toxodontid Adinotherium.
The dentition of Nesodon shows features typical of living grazing (grass-eating) mammals, but a study of wear on the enamel of N. imbricatus suggests that it was a browser (leaf eater) that may have supplemented its diet with fruit or bark.
02Classification
In 2014, a study identifying a new species of Nesodon, N. taweretus, resolved the families phylogenetic relations, deriving the cladogram shown below:
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||
03Distribution
Fossils of Nesodon have been found in:
Sources and credits
This article is adapted from the Wikipedia article “Nesodon”, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.
Images, from Wikimedia Commons:
- Nesodon imbricatus skeleton reconstruction.jpg by William Berryman Scott, Public domain
- Nesodon.jpg by Charles Robert Knight, Public domain
- Promegatherium nanum.JPG by Apokryltaros at English Wikipedia, CC BY 2.5
Fathomly is not affiliated with or endorsed by the Wikimedia Foundation. Spotted a problem? Tell us.