Oradectes

Oradectes Temporal range: Early Permian
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Amphibia
(unranked):	Reptiliomorpha
Suborder:	†Diadectomorpha
Family:	†Diadectidae
Genus:	†Oradectes Kissel, 2010
Species
†S. sanmiguelensis (Lewis and Vaughn, 1965 [originally Diadectes sanmiguelensis])

Oradectes (meaning "margin biter", from Latin ora (margin) and dectes (biter)) is an extinct genus of diadectid reptiliomorph. It is known from a single partial skeleton collected from the Early Permian Cutler Formation of Colorado in the United States. The type species, O. sanmiguelensis, was originally named as a species of Diadectes in 1965. It was given its own genus in 2010.

Description

The only material belonging to Oradectes is a partial skeleton known as MCZ 2989. This skeleton includes a complete skull, neck vertebrae, a partial pectoral girdle, the right forelimb, and some ribs. The skull is robust with spade-shaped teeth lining the jaws. The front teeth of the lower jaw protrude outward. A ventral border of the Meckelian fenestra of the lower jaw formed entirely from the splenial bone is a distinguishing feature of Oradectes found in no other diadectid.^[1]

Classification

Oradectes sanmiguelensis was described by Lewis and Vaughn (1965) as a species of Diadectes, D. sanmiguelensis. In a 2005 phylogenetic study of diadectids, D. sanmiguelensis was found to be one of the most basal diadectids and was placed far from a clade containing most of the other species of Diadectes.^[2] A 2010 analysis came up with the same results and assigned D. sanmiguelensis to the new genus Oradectes. Below is a cladogram from the 2010 study showing the phylogenetic position of Oradectes:^[1]

Diadectomorpha	Limnoscelidae Tseajaiidae  Diadectidae  Ambedus pusillus Oradectes sanmiguelensis Orobates pabsti Desmatodon hesperis Silvadectes absitus Diadectes tenuitectes Diadectes sideropelicus Diasparactus zenos

References

1. ^ ^{a b} Kissel, R. (2010). Morphology, Phylogeny, and Evolution of Diadectidae (Cotylosauria: Diadectomorpha). Toronto: University of Toronto Press. pp. 185. hdl:1807/24357. 
2. ^ Kissel, R.; Reisz, R.; and Berman, D. (2005). "Revisiting the taxonomy of Diadectidae (Cotylosauria: Diadectomorpha): a phylogenetic approach". Journal of Vertebrate Paleontology 25 (Supplement 3): 78A. 

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