CRANIAL REMAINS OF QUETZALCOATLUS (PTEROSAURIA, AZHDARCHIDAE) FROM LATE CRETACEOUS SEDIMENTS OF BIG-BEND-NATIONAL-PARK, TEXAS

Numerous remains of the azhdarchid pterosaur Quetzalcoatlus sp., have been recovered over the last twenty years from the Late Cretaceous (Ma astrichtian) rocks in Big Bend National Park in Trans-Pecos Texas. Amo ng more than 200 bones found at one locality are four incomplete skull s and mandibles, which provide the most complete information about cra nial structures in the Azhdarchidae. What is currently known indicates that the Azhdarchidae is the sister group of the Tapejaridae from Ear ly Cretaceous deposits in northeastern Brazil.