Wannchampsus is
based on SMU 76604, a partial skull and lower jaw. This fossil is attached by matrix to another partial skull of the same genus and species, SMU 76605. A handful of other fossils were found associated, mostly representing forelimbs and
vertebrae. These fossils were found in rocks of the late
Aptian-age Lower Cretaceous
Twin Mountains Formation, southwest of
Stephenville, in
Comanche County, Texas; the site is otherwise known as the
Proctor Lake dinosaur locality.
Wannchampsus was described in
2014 by Thomas Adams. The
type species is
W. kirpachi, in honor of Wesley Kirpach, "who was instrumental in the discovery and excavations of the type specimen". The skulls are described as "low and broad", and are small; SMU 76604 is estimated at long, and SMU 76605 is estimated at long. The lower jaw lacks external
mandibular fenestrae, and the third tooth of the
maxilla (main tooth-bearing bone of the upper jaw) and the fourth tooth of the
dentary (tooth-bearing bone of the lower jaw) are enlarged. The teeth become broader and less conical going back toward the jaw joint, and the teeth at the
anterior end of the lower jaw project forward (the anterior end of the upper jaw, composed of the
premaxillas, is not known). Features of the skull and vertebrae indicate that the individuals are subadults. Adams performed a
phylogenetic analysis and found
Wannchampsus kirpachi to be a
derived paralligatorid, closely related to the "
Glen Rose form", which he regarded as belonging to the genus
Wannchampsus. ==References==