Kingdom Animalia Stem group †Bidentalia Higher classification Dicynodont Order Therapsid | Infraorder †Dicynodontia Phylum Chordata Rank Genus | |
Similar Dicynodont, Therapsid, Anomodont, Synapsid, Endothiodon | ||
Rastodon is the oldest and most basal known genus of bidentalian dicynodont. Uniquely among dicynodonts, its tusks curve forward. The type and only species is R. procurvidens.
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Etymology
Rastodon is derived from the Rio do Rasto Formation, whence its remains came, and the Greek word for "tooth". The species name, R. procurvidens, means "curved forward tooth" and describes its uniquely shaped teeth.
Provenance
Only a single specimen of Rastodon has been discovered so far. It comes from the Rio do Rasto Formation, of the Guadalupian of Brazil.
Description
Rastodon is a fairly typical dicynodont. It bore a beaked head with a single pair of tusks and a keratin-covered nasal boss. However, it does possess several distinctive traits, of which its anteriorly-curved tusks are the most distinctive. Furthermore, its skull is relatively long and shallow compared to its close relatives. Its tusks contacted the lower jaw during propalinal mastication.
Classification
Rastodon is most parsimoniously placed as the basalmost bidental dicynodont, although it may be slightly more derived within Bidentalia.