Amphicotylus

Amphicotylus is an extinct genus of goniopholidid mesoeucrocodylian from the Tithonian of Colorado, Wyoming, and Oklahoma. It was described in 1878.

==Discovery and species== Amphicotylus was first described by Edward Drinker Cope in 1878 based on dorsal and lumbar vertebrae, ribs and osteoderms. Based on these remains, found in the same locality as Camarasaurus supremus, Cope determined the animal to have been smaller than the extant American Alligator and named the species A. lucasii after Superintendent Lucas who initially made the discovery. Cope also collected skull material from the same locality and level, however did not refer it to Amphicotylus. The cranial material was examined by Charles C. Mook in 1942 who referred it to the type species not only on the basis of its locality, but also its matching size, general morphological characters and the absence of any other crocodilian remains from the area. Mook furthermore uses this skull to establish a provisional neotype to account for the fragmentary nature of the original material described by Cope.