With its four wings and a long, bony tail, Microraptor was unlike any bird alive today. This is because it was a dinosaur—one that ... arms (and in Microraptor, legs) and getting off the ground.

An illustration shows what Duonychus tsogtbaatari might have looked like. Unlike its therizinosaur brethren, the new species ...

Paleontologists in Argentina recently found the first unambiguous evidence that a group of theropod dinosaurs had hollow ...

With distinctive two-fingered claws, the remains of a previously unknown species of dinosaur suggest it looked ... and it could have grasped branches up to 4 inches (10 centimeters) in diameter ...

Some dinosaurs that walked on four legs even had a different number of toes on their front and back feet - Stegosaurus had five toes on its front feet but just three on its back feet.