Pterosaurs (Pterosauria); now extinct. A dinosaur-era reptile (although not technically a dinosaur) is believed to have been the largest flying animal that ever existed: the pterosaur Quetzalcoatlus northropi. The maximum size of this soaring giant was believed to have been about 127 kg (280 lb) and 12 m (40 ft) across the wings. Some incomplete remains, however, demonstrate the existence of larger pterosaurs, with some estimates suggesting a maximum wingspan of 18 meters.