Sinopterus

Sinopterus (meaning "Chinese wing") is a genus of tapejarid pterodactyloid pterosaur from the Aptian-age Lower Cretaceous Jiufotang Formation of Chaoyang, Liaoning, China. It was first described and named by Wang Xiaolin and Zhou Zhonghe. Historically, there were multiple species attributed to the genus although only one is considered to be valid. Sinopterus is known for its proportionally large skull, which has a bird-like pointed beak lacking teeth, and a long bony crest that starts with a tall premaxilla and goes back along the middle of the skull to form a point overhanging the rear of the skull. Direct dietary evidence based on gut contents suggest that Sinopterus is a herbivore.

==History of discovery== thumb|left|Holotype specimen of S. dongi Sinopterus is known from numerous specimens, some of which have been assigned to unique species and even different genera over the years. The type species, Sinopterus dongi, is known from one specimen described in 2003. A second specimen, BPV-077, was also described in 2003 by Li, Lü, and Zhang, who classified it in its own species, S. gui. It was said to differ from S. dongi mainly in its smaller size (only about half the size of S. dongi) and the presence of a notarium, though this was later disproved. Some later studies found S. gui to simply represent a younger specimen of S. dongi, though one large analysis in 2014 found it to be a more primitive tapejarid.