A review of Leidyosuchus canadensis Lambe, 1907 (Archosauria: Crocodylia) and an assessment of cranial variation based upon new material

Abstract

Cranial morphology of Leidyosuchus canadensis Lambe 1907 is reviewed based on previously undescribed material—seven skulls and eight mandibles. This species can be distinctively diagnosed by more than 10 derived features. New information supports the contention that L. canadensis is the sole representative of Leidyosuchus, and indicates that it is very different from the other species previously assigned to this taxon. The membership of L. canadensis within Alligatoroidea is also demonstrated by new information revealed in this study. Ontogenetic and individual variation in the cranial anatomy of L. canadensis are documented. The contact of the premaxillary–maxillary suture with the incisive foramen is not diagnostic of the taxon; rather, it exhibits individual variation. Leidyosuchus is endemic to North America. There was no faunal interchange of crocodyliforms between North America and central Asia during the last two stages of the Late Cretaceous.