A NEW RHAMPHORHYNCHID PTEROSAUR FROM THE UPPER JURASSIC OF XINJIANG, CHINA, AND THE PHYLOGENETIC RELATIONSHIPS OF BASAL PTEROSAURS

A new rhamphorhynchid pterosaur species, Sericipterus wucaiwanensis, gen. et sp. nov., is described from the Upper Jurassic part of the Shishugou Formation in the Xinjiang Autonomous Region of northwest China. Pterosaurs from this unit are the earliest and only records of pterosaurs in the Jurassic of northwest China. The individual specimen is one of the largest known among 'rhamphorhynchoids,' or non-pterodactyloid pterosaurs. The holotype comprises an associated skeleton of mostly disarticulated, largely three-dimensional material. Although partly crushed, the preservation in this specimen reveals morphology rarely seen in non-pterodactyloid pterosaurs. This includes a distinct cervical intervertebral articulation morphology that is proposed to be widespread among the non-pterodactyloids. The skull of this new specimen is most similar to that of other rhamphorhynchids, Angustinaripterus longicephalus and Harpactognathus gentryii, found in terrestrial deposits. A phylogenetic analysis of 18 non-pterodactyloid pterosaurs and the Pterodactyloidea places Sericipterus wucaiwanensis with these species within the Rhamphorhynchinae and a monophyletic Rhamphorhynchidae. Unlike previous phylogenetic analyses, the Dimorphodontidae is paraphyletic, the Campylognathoididae is polyphyletic, and the Anurognathidae is the sister group of the Pterodactyloidea. Sericipterus wucaiwanensis, Angustinaripterus longicephalus, Harpactognathus gentryii represent a clade of large pterosaurs that likely lived in the terrestrial settings in which they preserved.