First Record of Endopterygoid Teeth in the North American Late Cretaceous Teleostean Fish Enchodus gladiolus (Aulopiformes: Enchodontidae)

Abstract

Abstract Teeth of the endopterygoid are described for the first time in the North American Late Cretaceous fish Enchodus gladiolus (Cope, 1872) from a previously described specimen from the Niobrara Chalk of Kansas. The teeth are located on the medial side of the bone with the greatest number concentrated at its posterior end. Most teeth consist of numerous small cones, but at the posterior end of the bone are several elongated teeth that run parallel to the length of the bone. E. lewesiensis (Mantell, 1822) and E. brevis Chalifa, 1989 are the only other two Enchodus species known to have endopterygoid teeth. Their teeth are very similar to those of E. gladiolus. Several fossil aulopiform genera besides Enchodus also have similar endopterygoid teeth. The endopterygoid teeth in E. gladiolus superficially resemble the tubercles found on other dermal bones. The presence of endopterygoid teeth in other fossil aulopiform taxa suggests that it may be a primitive condition.