Richard Crowley, age 12, of Peterborough, Ontario, Canada, for his question:

How was the pterodactyl able to fly?

Our modern birds are masters of the air and it is natural to suppose that no creatures of the past ever equaled the grace and power of their flight. For a long time, scientists were somewhat puzzled about the pterodactyls who took to the air during the days of the dinosaurs. Fossil evidence suggested that their flight was weak and clumsy. Recently the evidence was re evaluated and. it is thought that perhaps the pterodactyls even surpassed the flight of our modern bird world.

The term pterodactyl, meaning "wing fingers," was coined during the 1700s, when paleontologists first found sample fossils of these early flying animals. Later, with many more samples, their family tree was surveyed with astonishment. Though bird like, they were not birds and their descendants did not give rise to the modern birds. Some 20 species are now classified as pterosaurs, for they were flying reptiles and qualified members of the great saurian order of the dinosaurs. The earliest pterosaurs took to the air some 150 million years ago, during the heyday of the Age of Reptiles. Through the next 90 million years, nature improved them and they became supreme masters of the air.

All the pterosaurs, large and small, had lightweight bodies built for flight. Their slim bones were hollow and porous, their bodies were small in comparison with their wide wings. They had huge heads with long, pointed snouts. Earlier models had rows of sharp teeth in their jaws and long reptile tails. Later models were toothless, their wider tails were shorter and some had high crests of bone on their heads. All had small, weak legs and all wore reptile scales, rather than feathers.

The remarkable wings of the pterosaurs were bands of scaly skin, supported on the elongated bones of their arms and hands. The first three fingertips were free and fiercely clawed. These membrane wings resembled those of a modern bat and their flight was bat like. However, the best of them far surpassed the flight of any known bat. The early pterodactyls were no bigger than sparrows. The much later pteronodon were huge, their wings spanning 25 feet or more.

The mighty pteronodon was nature's supreme flying animal. Scientists suspect that he lived along rocky coasts and soared for long hours above the waves. Now and again he plunged down like a dive bomber to grab a fish in his toothless jaws. Maybe he used his finger claws to cope with a struggling victim. On land, his weak legs were clumsy, if not helpless. But the mighty air ace could have used his clawed fingers and toes to cling to the side of a rocky cliff. In the air, perhaps his short tail and the high crest on his head were used to steer and guide his flight. His immense wings flapped and wheeled, banked and turned, swooped and dived and, no doubt, out soared our soaring albatross.

No the pterosaurs were not the ancestors of the birds and none of their descendants exist in the modern world. After spending, 90 million years perfecting the mastery of flight, nature discarded them. All of these early flying aces became extinct about 60 million years ago. This was when, for reasons still unknown, all of their dinosaur kinfolk also departed forever from the earth.