Home Amphibians Birds Fish Mammals Reptiles

 
 
Pterosaur
           
                        PTEROSAUR (Gr. ptero, "feather, wing"; sauros, "lizard"), term applied to any flying
                        reptile of the order Pterosauria, which existed during the Mesozoic era from the Late
                        Triassic period nearly to the end of the Cretaceous period. Many fossil remains of
                        pterosaurs, which are often popularly referred to as pterodactyls, have been found in
                        all continents except Antarctica; about 60 genera have been discovered. Pterosaurs
                        did not have feathers. The wings were thin membranes of skin, similar to the wings
                        of a bat, which extended along the sides of the body, and were attached to the
                        extraordinarily long fourth digit of each arm. The bones were hollow and had
                        openings at each end. Unlike typical reptiles, pterosaurs had a breastbone that was
                        well developed for the attachment of flight muscles and a brain that was also more
                        developed. 

                        In early pterosaurs of the Late Triassic period, the best-known form of which is
                        Rhamphorhynchus, the skull was about 9 cm (about 3.5 in) long and the body was
                        about 10 cm (about 4 in) long. The flexible tail, which was about 38 cm (about 15 in)
                        long, had a diamond-shaped terminal appendage, used as a rudder in controlling
                        flight. Later pterosaurs of the Upper Cretaceous period, the best known of which is
                        Pteranodon, had a wingspread of more than 6 m (more than 20 ft). The skull was
                        long and slender and the jaws were toothless. Although later pterosaur forms were
                        fairly adept fliers, these creatures are not more ancestral to birds than are other
                        reptiles. 

                        Early in 1975 scientists announced that partial skeletons of three huge, long-necked
                        pterosaurs had been discovered in the Late Cretaceous nonmarine rock at Big Bend
                        National Park in Texas. With an estimated wingspan of approximately 11?12 m
                        (approximately 36?39 ft), the Big Bend pterosaur is the largest flying creature known
                        to have existed.