PHYTOSAURS (REPTILIA, ARCHOSAURIA) FROM THE UPPER TRIASSIC NEW OXFORDFORMATION OF YORK COUNTY, PENNSYLVANIA

An incomplete well-preserved skull of a small phytosaur from the Upper Triassic New Oxford Formation of York County, Pennsylvania, resembles skulls previously referred to Rutiodon carolinensis in the plesiomorp hic possession of a slender, uncrested rostrum. It differs from the la tter only in the course of the palatal suture between the premaxilla a nd maxilla and the sharply notched anterior margin of the supratempora l fenestra. The type species of Rutiodon Emmons, 1856, R. carolinensis from the Cumnock Formation of North Carolina, cannot be adequately di agnosed at present and is considered a metataxon sensu Gauthier (1986) . A very large tooth of a phytosaur from the same locality as the skul l is not conspecific with the latter and indicates the existence of a second, much larger phytosaur in the New Oxford Formation.