Paper No. 11-1
Presentation Time: 8:10 AM
ADDITIONAL CRANIAL MATERIAL OF THE JURASSIC BASAL GONIOPHOLID CROCODYLIFORM, CALSOYASUCHUS VALLICEPS
A more complete description of the skull of Calsoyasuchus valliceps, a Jurassic basal goniopholid crocodyliform from the Kayenta Formation, is presented. The incomplete holotype was described by researchers at the University of Texas-Austin in 2002. The holotype consists mainly of the rostral portion of the skull. The new specimen contains a more complete posterior portion of the skull, including a portion that duplicates the posterior region of the holotype, the braincase, cheeks and partial suspensorium. By visual examination of the specimen aided with CT scans, additional cranial character states can be documented. These include characters associated with the quadrate, quadratojugal, squamosal, pterygoid, basisphenoid, basioccipital, otoccipital, supraoccipital and others. With new characters from the second specimen, a more complete description of this early goniopholid is provided, further supporting what is known about the phylogeny of group. This additional material does not change the basal gonipholid position recovered in several recent analyses.