A Description of the Skull of Eubaena Cephalica (Hay, 1904) and New Insights into the Cranial Circulation and Innervation of Baenid Turtles

ABSTRACT

The internal carotid system has played an important role in the systematics of fossil turtles, including baenids. A new, almost perfectly preserved specimen of Eubaena cephalica provides an opportunity to explore for the first time the cranial circulation and innervation of this taxon using CT (computed tomography) scans. We here document that the skull possesses a well-developed, branching canalis nervus vidianus but lacks a canalis caroticus palatinum, which contradicts the previously reported circulation and innervation pattern for E. cephalica specifically and that of paracryptodires in general. Future investigation using CT scanning technology will be able to clarify if the pattern reported herein is unique to E. cephalica or is representative of paracryptodires in general. The latter conclusion will likely have considerable implications for the systematics of fossil turtles.

Citation for this article: Rollot, Y., T. R. Lyson, and W. G. Joyce. 2018. A description of the skull of Eubaena cephalica (Hay, 1904) and new insights into the cranial circulation and innervation of baenid turtles. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2018.1474886.

ACKNOWLEDGMENTS

We thank T. Tucker for preparing the skull described herein. C. Foth hand-carried the specimen from the U.S.A. to Switzerland, C. Neururer aided with CT scanning, and V. Volpato provided assistance with the digital manipulation of CT data. Donald Brinkman and an anonymous reviewer made suggestions that improved the manuscript. This study was funded by a visiting student grant to Y. Rollot from the International Office of the University of Fribourg and by the Department of Geosciences of the University of Fribourg.