Rastodon

Summary

Rastodon is an extinct genus of dicynodont. Uniquely among dicynodonts, its tusks curve forward. The type and only species is R. procurvidens.[1]

Rastodon
Temporal range: Mid-Late Permian
~268–259 Ma
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Synapsida
Clade: Therapsida
Suborder: Anomodontia
Clade: Dicynodontia
Clade: Bidentalia
Genus: RastodonBoos et al. 2016
Species
  • R. procurvidens Boos et al. 2016 (type)

Etymology edit

Rastodon is derived from the Rio do Rasto Formation, where its remains were found, and the Greek word for "tooth". The species name, R. procurvidens, means "curved forward tooth" and describes its uniquely shaped teeth.[1]

Provenance edit

Only a single specimen of Rastodon has been discovered so far. It comes from Guadalupian deposits found at an outcrop of the Rio do Rasto Formation at the Boqueirão Farm, in the municipality of São Gabriel, Rio Grande do Sul, Brazil. .

Description edit

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 edit

Rastodon has been recovered as the basalmost bidentalian dicynodont.[1] However, the phylogenetic position of Rastodon is contentious,[2] for it has also been recovered as the basalmost emydopoid dicynodont.[3]

See also edit

References edit

  1. ^ a b c Boos, Alessandra D. S.; Kammerer, Christian F.; Schultz, Cesar L.; Soares, Marina B.; Ilha, Ana L. R. (2016-05-25). "A New Dicynodont (Therapsida: Anomodontia) from the Permian of Southern Brazil and Its Implications for Bidentalian Origins". PLOS ONE. 11 (5): e0155000. Bibcode:2016PLoSO..1155000B. doi:10.1371/journal.pone.0155000. ISSN 1932-6203. PMC 4880204. PMID 27224287.
  2. ^ Kammerer, Christian F.; Ordoñez, Maria de los Angeles (June 2021). "Dicynodonts (Therapsida: Anomodontia) of South America". Journal of South American Earth Sciences. 108: 103171. Bibcode:2021JSAES.10803171K. doi:10.1016/j.jsames.2021.103171. ISSN 0895-9811. S2CID 233565963.
  3. ^ Macungo, Zanildo; Benoit, Julien; Fernandez, Vincent; Araújo, Ricardo M N (2022-06-01). "X-ray microcomputed and synchrotron tomographic analysis of the basicranial axis of emydopoid dicynodonts: implications for fossoriality and phylogeny". Zoological Journal of the Linnean Society. 198 (1): 1–46. doi:10.1093/zoolinnean/zlac033. ISSN 0024-4082.