In 2002, paleontologists dug up a dinosaur mummy -- the first one ever found.  

Watch this video of a dinosaur mummy being dug up in Montana, USA.  

Until this find, scientists had only fossilized skeletons of dinosaurs to study. This dinosaur was found complete with skin, muscle, beak and the remains of its last meal of pine trees and flowers. Leonardo is a 77-million-year-old fossilized mummy of a duck-billed, quadriped dinosaur known as brachylophosaurus, a herbivore. Leonardo is important because it provided so much information about a dinosaur's body and the environment in which dinosaurs lived.

The science: Forms of life on earth have changed over time. Dinosaurs were a class of creatures who lived for 160 million years, a period which ended about 60 million years ago. We can learn about them only by studying clues they left behind.