Late Cretaceous Marine Vertebrate Fauna from the Fairport Chalk Member of the Carlile Shale in Southern Ellis County, Kansas, U.S.A.

Abstract

The Fairport Chalk (middle Turonian) of the Carlile Shale is an Upper Cretaceous rock unit deposited in the middle of the Western Interior Seaway during the early regressive phase of the Seaway following its peak transgressive phase. The Sternberg Museum of Natural History in Hays, Kansas, U.S.A., houses a collection of marine vertebrate fossils from the Fairport Chalk in southern Ellis County, Kansas. The fossil fauna consists of at least 16 taxa, including 11 chondrichthyans, four osteichthyans, and one reptilian. They show wide ecological diversity, with examples of small to medium-sized opportunistic (Squalicorax), large predaceous (Cardabiodon and Cretoxyrhina), and durophagous (Ptychodus) sharks, as well as small (Enchodus), medium-sized (Plethodidae and Pachyrhizodus), and large (Ichthyodectes) bony fishes. Another notable finding is the occurrence of Telodontaspis agassizensis in which the species was previously known only from Cenomanian deposits, making the specimen from the Fairport Chalk the g...