|Named By:||Lu Junchang & Fucha Xiaohui in 2011|
|Time Period:||Middle Jurassic, 160 Ma|
|Location:||China, Liaoning Province - Tiaojishan Formation|
|Size:||Roughly estimated at 90 centimetre wingspan|
|Fossil(s):||Partial skull, mandible, and post partial incomplete skeleton|
|Classification:||| Chordata | Reptilia | Pterosauria | Pterodactyloidea | Istiodactylidae ||
Archaeoistiodactylus is an extinct genus of pterosaur from the Middle Jurassic of China. It is known from an incomplete skeleton with a partial skull and lower jaw recovered from rocks of the Tiaojishan Formation in western Liaoning, China. It was first named by Lu Junchang and Fucha Xiaohui in 2010 and the type species is Archaeoistiodactylus linglongtaensis. The authors of its description assigned Archaeoistiodactylus to the clade Breviquartossa and considered it to be more closely related to the istiodactylids than to any other group of pterosaurs; however, they considered it to be more primitive than the Cretaceous istiodactylids and regarded it as an ancestor, rather than member of istiodactylid pterosaurs. Martill and Etches (2013) suggest that the holotype specimen might actually be a poorly preserved specimen of Darwinopterus. Sullivan et al. (2014) considered the "distinctive midline tooth in the tip of the rostrum" of the holotype specimen to be a probable valid diagnostic feature of A. linglongtaensis; however, the authors considered it more likely that Archaeoistiodactylus was a basal monofenestratan than an istiodactylid.