Date of this Version
Fragmentary, dermal spines of Pennsylvanian chondrichthyans from Cass and Sarpy counties, Nebraska, are described. Forms that have been identified include the genera Acondylacanthus, Amelacanthus, Bythiacanthus, and "Physonemus" and an indeterminate hybodont. A diverse chondrichthyan fauna is therefore represented by these spines. The record of Amelacanthus is the first outside Great Britain and Northern Ireland.