PTERANODON

genus of extinct flying reptiles found as fossils in Late Cretaceous deposits (those 66.4 to 97.5 million years old) of Europe, Asia, and North America. Pteranodon, a highly developed form that marks the height of pterosaur evolution, was extremely large, with a wingspan of 7 m (23 feet) or more. Its toothless jaws were very long and pelican-like. A crest, present at the back of the skull, may have functioned as a sort of counterbalance to the long jaws. As compared with the wings, the body was small, only about as large as a modern turkey. Because of the relatively light weight the wings had to support, Pteranodon was an efficient glider; it is thought unlikely that the wings were flapped bird fashion since Pteranodon had a weakly developed sternum and lacked the keel at the breast to which the powerful flight muscles found in most birds attach. The eyes were relatively large, and the animal may have relied heavily upon sight. Pteranodon fossils are frequently found in rocks formed in marine environments, indicating that the animal spent much time gliding over the ocean waters searching for fish that must have made up the bulk of its diet. It is probable that Pteranodon took off from the ground by facing into sea breezes that provided enough force to lift its outstretched wings. It is likely that the animal exhibited nesting behaviour. See also pterodactyl; pterosaur.