A new azhdarchoid pterosaur from the Lower Cretaceous of China and its implications for pterosaur phylogeny and evolution.

Toothless pterosaurs played a key role in broadening the taxonomic, morphological and ecological diversity of Cretaceous pterosaurs. Here we report a complete, articulated skeleton of a 1.4-m-wingspan pterosaur from the Lower Cretaceous Jiufotang Formation of Liaoning Province, China which is identified as a new genus and species, Shenzhoupterus chaoyangensis gen. et sp. nov. The new taxon is edentulous, with a relatively large skull and a remarkably large, tall nasoantorbital fenestra that extends well above the main part of the braincase. Phylogenetic analysis shows that Shenzhoupterus gen. nov. belongs in a distinct clade of azhdarchoid pterosaurs, formally recognised here as a new family, Chaoyangopteridae, that also includes Chaoyangopterus, Jidapterus and Eoazhdarcho from the Jiufotang Formation and Eopteranodon from the Yixian Formation. These new data clarify recent confusion surrounding the systematics of these Lower Cretaceous taxa and provide new insights into the evolutionary history of pterosaurs.