A NEW SPECIMEN OF UTATSUSAURUS (REPTILIA, ICHTHYOSAURIA) FROM THE LOWER TRIASSIC SULFUR MOUNTAIN FORMATION OF BRITISH-COLUMBIA

An incomplete skull and mandible of the primitive ichthyosaur Utatsusa urus is described from the Lower Triassic Vega Phroso Member of the Su lphur Mountain Formation of British Columbia. The specimen contributes to our knowledge of the cranial anatomy of the genus, which was previ ously known primarily from postcranial material, and extends its geogr aphic range to Canada. The presence of an isodont dentition in this pr imitive genus suggests that isodonty rather than heterodonty may be th e primitive character state for the Ichthyosauria.