<i>Terminonaris</i>(Archosauria: Crocodyliformes): new material from Saskatchewan, Canada, and comments on its phylogenetic relationships

Abstract

ABSTRACT A newly-discovered skeleton of Terminonaris (=Teleorhinus) robusta (=robustus) from the early Turonian marine deposits of east-central Saskatchewan affords the opportunity for a detailed description of the anatomy of this species and its placement in the context of other known species of this genus. The specific diagnosis of T. robusta and the generic diagnosis of Terminonaris are established. Terminonaris robusta differs from the type species T. browni mainly in size-related features. Teleorhinus mesabiensis Erickson, 1969 is placed into the synonymy of Terminonaris robusta. The genus can be diagnosed by features of the anterior end of the snout, suturai relationships of the bones surrounding the orbit, and the structure of the occiput. A phylogenetic analysis based upon data drawn from the new material suggests that Terminonaris is not a pholidosaurid but is, instead, closely related to Dyrosaurus. This analysis continues to support the hypothesis that long-snouted crocodyliforms of the traditional “mesosuchian grade” form a clade.