Erpetosuchus

Erpetosuchus is an extinct genus of crurotarsan from the Late Triassic. It was first described by E. T. Newton in 1894 for remains found in northeastern Scotland, with more remains found in the United States in recent years. Erpetosuchus is the sister-taxon to Crocodylomorpha.

The type species of Erpetosuchus is E. granti.

Material
The first remains of Erpetosuchus were found in the Lossiemouth Sandstone Formation in Scotland (late Carnian, Late Triassic), and consist of a skull and a partial postcranial skeleton. The holotype is BMNH R3139

During a field trip in 1995 to the lower part of the New Haven Formation in Connecticut, American palaeontologist Paul E. Olsen discovered a partial skull that, after preparation and description in 2000 (Olsen et al. 2000), was referable to E. granti. This was the first record of E. granti outside of Scotland. The specimen has been given the number AMNH 29300, and besides the right side of the skull, also has some vertebrae and indeterminate bones associated. Dating of the lower portion of the New Haven Formation indicates a Norian (Late Triassic) age.

Systematics
Erpetosuchus granti was originally assigned to Thecodontia, but that name no longer appears in scientific literature because it is a paraphyletic group, consisting of distantly related archosaurs. It has also been considered a crocodylomorph, included within the clade Erpetosuchia, or as a pseudosuchian.

A more recent phylogenetic analysis by Olsen et al. (2000) found E. granti to be the sister-taxon to the Crocodylomorpha. These are united in a clade by the following synapomorphies:


 * Medial contact of the maxillae to form a secondary bony palate
 * Absence of a postfrontal
 * Parietals fused without a trace of an interparietal suture