Some observations on Denaea fournieri (Chondrichthyes, Symmoriiformes) from the Lower Carboniferous of Belgium

Abstract

Preliminary observations are presented concerning endoskeletal morphology in the Lower Carboniferous symmoriiform shark Denaea fournieri, and some problems in the original description are highlighted. D. fournieri almost certainly possessed a tropibasic braincase and its cranial morphology agrees in most respects with that observed in other symmoriiforms, although it had an extremely narrow ethmoidal region and may have lacked supraorbital cartilages. Its pectoral fins were probably similar to those of other symmoriiforms, and the radialbearing margin of its metapterygium most closely resembles that of falcatids and Stethacanthulus. Using Cladoselache as an outgroup, several apomorphic characters are identified in symmoriiform pectoral fins.