THE OCCURRENCE OF CONTOGENYS-LIKE LIZARDS IN THE LATE CRETACEOUS AND EARLY TERTIARY OF THE WESTERN INTERIOR OF THE USA

摘要

Based on diagnostic jaw and dental material from the Cenomanian-middle Paleocene of the western U.S.A.. we erect a new fossil lizard taxon, Contogeniidae taxon nov., that contains the following species: Contogenys sloani Estes, 1969 (Maastrichtian-early Paleocene, Montana) Contogenys ekalakaensis sp. nov. (middle Paleocene. Montana): Palaeoscincosaurus middletoni Sullivan and Lucas, 1996 (early Paleocene, Colorado) Palaeoscincosaurus pharkidodon sp. nov. (Campanian, Utah) Utahgenys evansi gen. et sp. nov. (Turonian, Utah); and Utahgenys sp. indet. (Cenomanian, Utah). These taxa share unique characteristics of tooth and jaw morphologies (e.g., tooth crowns truncate and bearing longitudinal apical grooves; hypertrophied inferior alveolar canal), Phylogenetic analysis, indicates that among squamates. Contogeniidae taxon nov. is most closely related to Xantusiidae.