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One Weird Dinosaur!

--By Dina El Nabli

Imagine a dinosaur small and light enough to glide from tree to tree. Now imagine it with four wings! Sound like something out of a science-fiction movie? Well, scientists in China have proof that such creatures existed about 130 million years ago. They found fossils of four-winged dinosaurs in China's Liaoning province, northeast of Beijing.

The dinosaur was about the size of a pheasant. It had one set of feathered wings on its forelimbs and another on its hind legs. Even its long tail was covered with feathers. Researchers named it Microraptor gui. (Microraptor means small predator; gui honors Chinese paleontologist Gu Zhiwei.) The discovery was announced last week in the science journal Nature.

FEATHERED FREAK

Paleontologists are fascinated by the unique fossil find. "It would be a total oddity--the weirdest creature in the world of dinosaurs and birds," said Luis Chiappe, a paleontologist at the Natural History Museum of Los Angeles County in California.

The discovery is reviving a hot scientific debate over two theories of how dinosaurs may have evolved into modern birds. The first theory says the ancestors of birds lived on the ground but used wings to increase their running speed. They eventually developed the ability to lift off. The second theory says that bird ancestors lived in trees and used wings to glide from tree to tree. Flying evolved from gliding.

The new fossil strongly supports the second theory. Scientists believe Microraptor gui was a glider that moved like today's flying squirrels.

The Microraptor belongs to a large category of lightweight, meat-eating dinosaurs called theropods. Its closest known relatives may be dromaeosaurs (dro-me-uh-sawrs), which had feathers but did not fly.

Paleontologist Xing Xu, who led the discovery team, says Microraptor is the best example yet of the transition from dinosaurs to birds. Mark Norell, a paleontologist at the American Museum of Natural History, told TFK that the fossils bring up new questions about how animals began to fly. "The origin of flight is a lot more complex than we thought it was," he says.

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THEY HAVE SO MUCH IN COMMON!

Besides feathers, theropod dinosaurs and birds both have...

LIGHT, HOLLOW BONES A bird's light bones enable it to fly. Other types of dinosaurs had heavy skeletons, but quick-moving theropods had light frames.

LONG, THIN SHOULDER BLADES

A WISHBONE The wishbone is where two clavicles meet. Clavicles connect the shoulders to the rib cage and breastbone.

SWIVELING WRISTS Curved bones allow the hands to fold against the lower arm.

THREE-CLAWED FEET In both birds and dinosaurs, the middle claw is longest.

LEGS AND FEET BUILT FOR TWO-LEGGED WALKING Theropods had arms but walked only on their hind legs. Like birds, they had three forward-pointing toes.

Next: Penguins on the Go