<i>Quebecius quebecensis</i> (Whiteaves), a porolepiform crossopterygian (Pisces) from the Late Devonian of Quebec, Canada

Abstract

Quebecius quebecensis (Whiteaves 1889) is a porolepiform crossopterygian related to Glyptolepis. A large nariodal, a large tabular, a separate intertemporal, and a large fused nasosupraorbital are features of Quebecius that characterize it as a porolepiform. The small size of the operculum, median extrascapular larger than the lateral one, small lower squamosals, and deep maxilla are additional features separating Quebecius from Glyptolepis. As in Glyptolepis, the median fins are not lobed. The pectoral fin possesses a long fleshy lobe. The internal, ventral side of the broadly based pelvic fin suggests that the internal axis has shifted towards the body. Pectoral fins with a long fleshy lobe are a common feature of porolepiforms, but lobed bases in the pelvic and unpaired fins are a feature found in Holoptychius, and not in Glyptolepis and Quebecius. Quebecius quebecensis is conspecific with Quebecius williamsi Schultze 1973, mistakenly described as an onychodont crossopterygian.