The holotype of Junggarsuchus sloani, from the early Late Jurassic of Xinjiang, China, consists of a nearly complete skull and the anterior half of an articulated skeleton, including the pectoral girdles, nearly complete forelimbs, vertebral column, and ribs. Here we describe its anatomy and compare it to other basal crocodylomorphs, based in part on CT scans of its skull and that of Dibothrosuchus elaphros from the Early Jurassic of China. Junggarsuchus shares many features with a cursorial group of crocodylomorphs, informally known as ‘sphenosuchians,’ whose relationships are poorly understood. However, it also displays several derived crocodyliform features that are not found among most members of this group. A phylogenetic analysis corroborates the hypothesis that Junggarsuchus is closer to Crocodyliformes, including living crocodylians, than are Dibothrosuchus and Sphenosuchus, but not as close to crocodyliforms as Almadasuchus and Macelognathus, and that the “Sphenosuchia” are a paraphyletic assemblage. Dibothrosuchus elaphros and Sphenosuchus acutus are hypothesized to be more closely related to Crocodyliformes than are the remaining ‘Sphenosuchia,’ which form several smaller groups but are largely unresolved.

CT scans of skulls processed in the program MIMICS.  

Phylogenetic data in Mesquite database

Phylogenetic analysis in TNT