A new crocodyloid (Eusuchia: Crocodylia) from the Upper Cretaceous of China

Abstract

Jiangxisuchus nankangensis gen. et sp. nov. is described on the basis of a nearly complete skull and mandible from the Upper Cretaceous of China. It is the only representative of the Crocodyloidea truly known in the Cretaceous of China on the basis of a set of cranial features, such as the palatine not extending significantly beyond the anterior end of the suborbital fenestra and the fronto-parietal suture making modest entry into the supratemporal fenestra at maturity. Within the Crocodyloidea, J. nankangensis is one of the basal forms and differs from other crocodyloids mainly in the following features: the nasals entering the single external naris; the interfenestral region of the skull roof narrow, about half the width of the interorbital region; the medial margin of the supratemporal fossa rimmed; the squamosal and quadrate entering the dorsal margin of the infratemporal fenestra; the supraoccipital exposed on the skull roof; the maxilla excluded from the large incisive foramen; the palatine shorter than the suborbital fenestra in length; the internal choana divided by a septum; the splenial not entering into the mandibular symphysis; and diastemata present at the premaxillary-maxillary suture, between the seventh and eighth maxillary teeth, and between the ninth and tenth dentary teeth. The discovery of J. nankangensis not only expands the paleogeography of the Crocodylia into Asia during the Cretaceous, but also provides new information for understanding the early history of the group.