Doswellia kaltenbachi (Weems 1980) Carnian, Late Triassic ~220mya, 1.60 m long, is an enigmatic pararchosauriform derived froma sister to the RC91 specimen of Youngoides and otherwise related to the clade Choristodera, including Champsosaurus, Cteniogenys and Lazarussuchus. Virtually everything about Doswellia was wider and flatter.
Distinct from RC91, the skull of Doswellia was wider and flatter. The orbits opened dorsally. The lateral temporal fenestra disappeared between the expanding jugal and squamosal. The mandible, and especially the surangular, was deeper than the skull. A long, narrow dentary was lined with sharp teeth.
The cervicals were elongated with wide cervical ribs. The anterior dorsal ribs had corners, creating a boxlike anterior. The posterior dorsal ribs extended laterally without any curve at all further posteriorly. The ilium was rotated laterally to the horizontal plane. The pubis and ischium were rotated medially.
Nothing but a short, sinuous femur is preserved of the limbs.
A recent study by Dilkes and Sues (2009) nested Doswellia with Proterochampsidae. Unfortunately they did not choose to include Youngoides or any choristodere, which is why their results had such poor support values.
Rugarhynchos sixmilensis (Wynd et al. 2020; Late Triassic; below) was originally considered a species of Doswellia (Heckert et al. 2012), but later a new genus was erected. |
