The braincase of Syllomus aegyptiacusLydekker, 1899 (Reptilia, Testudines) from the Middle Miocene Calvert Formation of Virginia

Abstract

The braincase of the marine turtle Syllomus aegyptiacus (Calvert Formation, Virginia, Middle Miocene) is described and figured in detail for the first time. It reveals a ventral crest on the basisphenoid, a high dorsum sellae, an almost subequal diameter of the canals for the internal and lateral carotid arteries at a cross break and a canalis caroticus lateralis and internus that are still far separated from each other at level of the dorsum sellae. The braincase is compared to other known braincases of fossil and extant chelonioid turtles.