The osteology of Azhdarcho lancicollis Nessov, 1984 (Pterosauria, Azhdarchidae) from the Late Cretaceous of Uzbekistan

Abstract

The osteology of the azhdarchid pterosaur Azhdarcho lancicollis Nessov, 1984 from the Late Cretaceous (Turonian) of Uzbekistan is described in detail based on more than 200 bone fragments representing several skull bones, cervical and dorsal vertebrae, pectoral girdle, and limb bones. Azhdarcho lancicollis is characterized by relatively short dentary symphysis and hyperelongated middle cervical vertebrae. The relative length of the cervicals is expressed by the formula I+II < III < IV < V > VI > VII > VIII > IX. The osteology in all azhdarchids is remarkable uniform but Azhdarcho can be distinguished from all other known azhdarchid genera. The phylogenetic analysis showed that the Turonian Azhdarcho and the Santonian Bakonydraco occupy a phylogenetic position basal to the Campanian Zhejiangopterus and the Maastrichtian Quetzalcoatlus.