Azhdarchidae

Azhdarchidae, the name of a dragon in Uzbek mythology, derived from the Persian Aži Dahāka) is a family of pterosaurs known primarily from the Late Cretaceous Period, and which included some of the largest known flying animals of all time. Originally considered a sub-family of Pteranodontidae, Nessov (1984) named the azhdarchinae to include the pterosaurs Azhdarcho, Quetzalcoatlus, and "Titanopteryx" (now known as Arambourgiania). Azhdarchids are characterized by their long legs and extremely long necks, made up of elongated neck vertebrae which are round in cross section. Most species of azhdarchids are still known mainly from their distinctive neck bones and not much else. The few azhdarchids that are known from reasonably good skeletons include Zhejiangopterus and Quetzalcoatlus. Azhdarchids are also distinguished by their relatively large heads and long, spear-like jaws. It had been suggested azhdarchids were skimmers, but further research has cast doubt on this idea, demonstrating that azhdarchids lacked the necessary adaptations for a skim-feeding lifestyle, and that they may have led a more terrestrial existence similar to modern storks.

Systematics
Azhdarchids were originally classified as close relatives of Pteranodon due to their long, toothless beaks. Others have suggested they were more closely related to the toothy Ctenochasmatids (which include filter-feeders like Ctenochasma and Pterodaustro). Currently it is widely agreed that azhdarchids were closely related to pterosaurs such as Tupuxuara and Tapejara.

Taxonomy
Classification after Unwin 2006, except where noted.


 * Family Azhdarchidae
 * Aralazhdarcho
 * Arambourgiania
 * Azhdarcho
 * Bakonydraco
 * Hatzegopteryx
 * Montanazhdarcho
 * Phosphatodraco
 * Quetzalcoatlus
 * Volgadraco
 * Zhejiangopterus
 * Possible valid azhdarchid genera
 * Eoazhdarcho
 * Doratorhynchus
 * Bogolubovia
 * Bennettazhia
 * "Ornithocheirus" bunzeli