A new species of dissorophid (Cacops woehri) from the Lower Permian Dolese Quarry, near Richards Spur, Oklahoma

ABSTRACT

A new species of Cacops, C. woehri, is described on the basis of a well-preserved skull from the Dolese Quarry locality in Oklahoma (Leonardian). Although its relatively small size and pattern of sculpturing indicate that the specimen probably represents a sub-adult individual, C. woehri differs from other members of the genus in the shallower shape of the skull, more dorsally located orbits, a distinct sculpturing pattern of radial ridges and grooves, and an ‘L’-shaped, narrow opening in the tympanic embayment. In addition, it differs from C. morrisi, the other anatomically well-known species of the genus, in the presence of a small posterior process of the postorbital contacting the supratemporal, in the presence of an ectopterygoid fang, large occipital flanges of the postparietal and tabular, and in the shape of the basal plate of the parasphenoid. This new taxon highlights the morphological diversity of species within the enigmatic genus Cacops, with variation encompassing a distinct cranial morphology.

ACKNOWLEDGMENTS

We would like to thank N. Wong Ken for the preparation of the drawings in Figures 1–4 and D. Scott for help with the preparation of the specimen. We thank D. Woehr, B. May, B. Dunn, and M. Feese for their enthusiastic support of research on the Dolese Fauna. We also wish to thank the staff of the Sam Noble Natural History Museum of Oklahoma for their continued support. Research was supported by a research fellowship of the German Research Foundation (DFG) to N.B.F. and an NSERC Discovery Grant to R.R.R.

Handling editor: Jason Anderson