Cenomanian (Late Cretaceous) reptiles from northwestern Russell County, Kansas

Abstract

ying reptile in Kansas; and (4) the rare aquatic lizard Coniasaurus. Several morphologic characters of B. lucasi are clarifi ed: an apomorphy in the paddle of B. lucasi are clarifi ed: an apomorphy in the paddle of B. lucasi B. lucasi where both the fourth and fimetapodials intrude on the mesopodial row is noted for the fi rst time; and striations of tooth enamel vary from the tooth crown to the root and from the front to the back of the tooth. Additionally, the stratigraphic occurrence of B. lucasi suggests that the minimal stratigraphic range for that species is from the late Cenomanian through middle Turonian. This diverse reptile fauna occurs with a variety of fossil ficonsisting of at least twelve chondrichthyan and four osteichthyan taxa. The age of the fauna is middle Cenomanian based upon the site’s stratigraphic occurrence and a radiometric date of 95.53 ± 0.159 Ma obtained one meter below the excavation. Whereas reptilian faunas of this age from the eastern margin of the Cretaceous Interior Seaway are relatively rare, this faunal assemblage adds signifi cant paleoecological information about Western Interior Basin biogeography.