Oradectes is an extinct genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of diadectid reptiliomorph. It is known from a single partial skeleton collected from the Early Permian Cutler Formation

Cutler Formation

The Cutler is a rock unit that is spread across the U.S. states of Arizona, northwest New Mexico, southeast Utah and southwest Colorado. It was laid down in the Early Permian during the Wolfcampian stage. In Arizona and Utah it is often called the Cutler Group but the preferred USGS name is Cutler...

 of Colorado

Colorado

Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...

 in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. The type species

Type species

In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...

, O. sanmiguelensis, was originally named as a species of Diadectes

Diadectes

Diadectes was a genus of large, very reptile-like amphibians that lived during the early Permian period...

in 1965. It was given its own genus in 2010.

Description

The only material belonging to Oradectes is a partial skeleton known as MCZ

Museum of Comparative Zoology

The Museum of Comparative Zoology, full name "The Louis Agassiz Museum of Comparative Zoology", often abbreviated simply to "MCZ", is a zoology museum located on the grounds of Harvard University in Cambridge, Massachusetts. It is one of three museums which collectively comprise the Harvard Museum...

 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

Splenial

The splenial is a small bone in the lower jaw of reptiles, amphibians and birds, usually located on the lingual side between the angular and suprangular....

 bone is a distinguishing feature of Oradectes found in no other diadectid.

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

Basal (phylogenetics)

In phylogenetics, a basal clade is the earliest clade to branch in a larger clade; it appears at the base of a cladogram.A basal group forms an outgroup to the rest of the clade, such as in the following example:...

 diadectids and was placed far from a clade containing most of the other species of Diadectes. A 2010 analysis came up with the same results and assigned D. sanmiguelensis to the new genus Oradectes. Below is a cladogram

Cladogram

A cladogram is a diagram used in cladistics which shows ancestral relations between organisms, to represent the evolutionary tree of life. Although traditionally such cladograms were generated largely on the basis of morphological characters, DNA and RNA sequencing data and computational...

 from the 2010 study showing the phylogenetic position of Oradectes: