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Giants Of The Sky

Millions of years ago, when dinosaurs ruled the earth, winged lizards, called pterosaurs (tear-a-sores), ruled the skies. Some were huge. The beast named Quetzalcoatlus (kwet-zal-coe-aht-lus) was the size of a small plane. It was nearly 20 feet long, and its wings stretched out 40 feet. Other pterosaurs were as small and as delicate as robins.

The first pterosaurs appeared about 200 million years ago-- almost 70 million years before the first known bird! Like their dinosaur cousins, pterosaurs lived on earth for millions of years; then they died out. When pterosaurs became extinct about 65 million years ago, they left behind fossils, footprints and some puzzling mysteries.

Scientists met in New York City in October to talk about the ancient creatures. For years, scientists have wondered, How did these extraordinary beasts fly? Did they take off by running along the ground or by dropping from a tree and then gliding? What on earth did these creatures eat? Were their tastes and behaviors similar to those of modern sea- and shorebirds?

Re-Creating A Lost World
Researchers cannot agree on many answers about the pterosaurs. "Apart from the fact that they flew, there isn't a thing that all the experts agree on," says scientist Kevin Padian. "How can animals that are so familiar to generations of schoolchildren be so confusing to the people who study them?"

Still, scientists have managed to learn quite a bit about pterosaurs. They know that the first pterosaurs share a common ancestor with the dinosaurs and appeared on earth about the same time. These early models had long bony tails that helped keep them stable in flight. Like birds, pterosaurs had light, hollow bones, but their wings were distinct. Pterosaurs had three clawlike fingers of normal size and a fourth finger that was very, very long. This fourth finger supported the wing.

Re-creating the lost world of pterosaurs is difficult. While today's birds are believed to be related to dinosaurs, pterosaurs have no descendants. "In the living world," says German expert Peter Wellnhofer, "there's nothing really like a pterosaur."

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Wing Tip: Clues From A Fossil
Pterosaurs' featherless wings are different from the wings of bats and birds. Bird wings extend along the bird's arm and hand bones. Bat wings are supported by four fingers. But, as this fossil of a robin-size pterosaur shows, pterosaur wings stretched along the animal's long fourth finger.

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