A new ichthyosaur from the Upper Cretaceous Mowry Formation of Wyoming

Abstract

Myopterygius americanus n. sp. is based upon the first spe cifically identifiable ichthyosaur remains found in the Cretaceous of North America, and is probably one of the most complete known post-cranial skeletons of this genus. Previous finds of ichthyosaurian remains in the North American Cretaceous, consisting only of fragmentary vertebral cen tra, have not been generically identifiable. The present specimen is described in detail and adds materially to our knowledge of the s keleton of the latestand most specialized of the ichthyosaur genera.