First occurrence of marine vertebrates in the Early Cretaceous of Kansas: Champion Shell Bed, basal Kiowa Formation

摘要

The Champion Shell Bed, the lowest defined lithostratigraphic unit of the Kiowa Formation that conformably overlies the Cheyenne Sandstone, is exposed near Belvidere in Kiowa County, south-central Kansas. The Champion Shell represents the earliest marine deposit that formed in the region as the Western Interior Sea advanced northward into the Midwest during the latter part of the Early Cretaceous (Upper Albian). Although invertebrate remains are abundant, the shell bed also contains the minute teeth of sharks and bony fish. The Champion Shell Bed provides the first records of marine vertebrate species from the Early Cretaceous of Kansas following a long hiatus of marine deposition extending back to the Upper Permian.