Parallel fibers that stiffened a pterosaur's wing membrane—each just two-thousandths of an inch (0.05 millimeters) thick—are visible in this fossil of a Rhamphorhynchus. The fossil was found in Germany's Solnhofen limestone beds, where incredibly fine grain preserves minute details.
... "Pterosaurs were just the coolest things that were ever in the air," says Padian. "They were the first vertebrates to fly. They did it long before birds and bats. And it terms of size, they pushed the envelope as far as it could go for a flying animal."
Like their cousins the dinosaurs, pterosaurs stand out as one of evolution's great success stories. They first appeared during the Triassic period, 215 million years ago, and thrived for 150 million years before going extinct at the end of the Cretaceous period. Their endurance record is almost inconceivable compared with the span of humans, whose ancestors started walking upright less than four million years ago. Uncontested in the air, pterosaurs colonized all continents and evolved a vast array of shapes and sizes. Of more than 120 named species, the smallest pterosaur measured no bigger than a sparrow; the largest reached a wingspan of nearly 40 feet (12 meters), wider than an F-16 fighter.
Until recently most paleontologists would not have put pterosaurs in the same league as birds in terms of flying ability. Because pterosaurs were reptiles, generations of scientists imagined that these creatures must have been cold-blooded, like modern snakes and lizards, making them awkward aerialists at best.
In the past three decades, however, a surge of fossil discoveries around the globe has prompted researchers to reexamine their views. The emerging picture of pterosaurs reveals that they were unlike any modern reptile. From a fossil discovered in Kazakhstan, paleontologists suspect that pterosaurs had a hairlike covering, perhaps akin to fur. If so, this detail provides evidence of a high-revving, warm-blooded physiology that could sustain the kind of exertion needed to stay in the air. Judging from the skulls of other fossils, scientists reason that many pterosaurs were gifted air-borne predators, built to feed on the wing. They darted after insects, dive-bombed for fish, and soared hundreds of miles over open ocean on extended hunting expeditions.