Abstract

An ichthyosaur skull from the Mowry Shale of Wyoming--the only good ichthyosaur skull so far known from the Cretaceous--is described and figured. Study of the well-preserved temporal region leads to the conclusion that the dermal element usually described in ichthyosaur skulls above the quadratojugal is nonexistent; that, hence, the large element bounding the temporal opening is the true squamosal, and the opening is thus of a typical euryapsid pattern. Illustrations of a Liassic ichthyosaur prepared by D. M. S. Watson are appended.

This content is PDF only. Please click on the PDF icon to access.

First Page Preview

First page PDF preview
You do not currently have access to this article.