Archaeoistiodactylus

extinct genus of wukongopterid pterosaur from the Middle Jurassic of China.^[1]

lower jaws. Catalogued as holotype specimen JPM04-0008, it was recovered from rocks of the Tiaojishan Formation in western Liaoning, China, which date to the Bathonian-Callovian stages of the Jurassic period. Apart from the skull, it preserves ribs, parts of the wings, hindlimbs and the pelvis. The neck, tail and feet of the specimen are lacking.^[1]

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.^[1] David Martill and Steve Etches in 2013 suggested that the holotype specimen might actually be a poorly preserved specimen of Darwinopterus.^[2] In 2014, Corwin Sullivan and colleagues 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.^[3] Later, when included in a phylogenetic analysis, Archaeoistiodactylus fell in a polytomy with wukongopterids, providing further support for an affinity with the clade.^[4] The 2021 description of Kunpengopterus antipollicatus followed this classification, but considered Archaeoistiodactylus to be an undiagnostic wukongopterid.^[5]