Pterosaur << TEHR uh sawr >> was a member of an extinct group of flying reptiles. Pterosaurs lived in the Mesozoic Era, from about 250 million to 65 million years ago. Their fossils have been found on every continent.
There were two major kinds of pterosaurs—rhamphorhynchoids and pterodactyls. Rhamphorhynchoids developed first. Most members of this group had a narrow face, a short neck, and a long tail. A species called Dimorphodon possessed an especially large head. The group also included the smallest pterosaurs, such as the sparrow-sized Anurognathus. Pterodactyls were more advanced and varied in size. They had a longer face and neck and were almost tailless. The Pteranodon, a large pterodactyl, had a crest at the back of its head. Another pterodactyl, Quetzalcoatlus, ranks as the largest known flying animal. Its wingspan ranged from 36 to 39 feet (11 to 12 meters).
At one time, experts believed that pterosaurs flew poorly and used their wings only for gliding. Most scientists now think pterosaurs were good fliers that flapped their wings up and down. Only some of the larger and more specialized forms seem to have been suited chiefly for soaring and gliding. Pterosaurs had light, hollow bones. Three clawed fingers and a long fourth finger extended from the end of each forelimb. Each wing consisted of a membrane that stretched from the side of the body to the tip of the fourth finger. Fine, parallel fibers prevented the wing from tearing. Short, featherlike structures called pycnofibers covered the body of some pterosaurs and kept them from losing body heat. Pterosaurs may have been able to run on their hind legs, but probably they were clumsy on land.
Pterosaurs ate other animals. The smaller forms probably ate insects. Some of the larger pterosaurs fed on fish, lizards, and other small vertebrates (animals with backbones).
