Mummified Dinosaur Revealed

A dinosaur fossil covered with mineralized skin, scales, and muscles opens a window to dinosaur life.

A fossil dinosaur nicknamed Leonardo is the new star of the paleontological community. Nearly all the specimen's external soft tissues-including skin, scales, muscles, and a beak-are preserved, inspiring scientists to classify it as a mummy. Less than one-tenth of a percent of all dinosaur fossils pulled from the ground have sported soft tissue. The finding offers a rare look at the dinosaur's movement, appearance, diet, and even environment when it walked the Earth about 77 million years ago.

Leonardo, named after graffiti at the site, is one of the most complete brachylophosaurus duck-billed dinosaurs discovered to date. Unearthed in northern Montana, it's only the fourth dinosaur "mummy" ever found, and the only one extracted with advanced excavation and preservation techniques so that its features are all intact. The others were discovered in the early 1900s.

Using modern technology, researchers will be able to scrape together the animal's most elusive secrets. Preserved shoulder muscles will reveal the size of the once-living animal's step, its range of motion, and whether it walked on two legs or all fours. Throat tissue, skin from all over the body, and pads on the bottom of three-toed feet will all provide more clues down the line.

Leonardo was a 22-foot-long juvenile about three or four years old when he died. He had five-sided scales, and probably a long frill that ran up his back like a mythical dragon. He was a vegetarian, and his last supper was a leafy salad of ferns, conifers, and magnolias peppered with pollen from more than 40 different types of plants

Map: Colleen Sudukem
Artist Greg Wenzel's rendering of the duck-billed dinosaur, brachylophosaurus.
Photo: National Geographic Society website.
After 77 million years, this subadult brachylophosaurus reveals the features of his immature face. Notice the well preserved beak.
Photo: Courtesy Judith River Dinosaur Institute

Paleolife artist and staffer of the Judith River Dinosaur Institute, Greg Wenzel, starts the grid site map of a section of Leonardo's tail.
Photo: Courtesy Judith River Dinosaur Institute
Close up of the skin impression on left forearm.
Photo: Courtesy Judith River Dinosaur Institute