Scientists dig up secrets from dinosaur mummy

— -- A 67-million-year-old dinosaur discovered by a high school sophomore in North Dakota has proven to be one of the most complete dinosaur mummies ever discovered. The specimen includes fossilized skin and tendons, allowing scientists to reconstruct its musculature in ways previously difficult to do.

A team led by Phil Manning, a paleontologist at the University of Manchester in England, unearthed the dinosaur in 2006, but its discovery is being announced today by the National Geographic Society, which provided the major funding.

The hadrosaur is "probably one of fewer than 10" such dinosaur mummies that have been found, says Matthew Carrano, curator of dinosauria at the Smithsonian. "To have the three-dimensional shape of the dinosaur, to have all of that together, is just extremely rare."

Hadrosaurs were about 25 to 30 feet long and stood 6 to 8 feet tall at the hip. They lived at the same time as the T. rex, in the last major flowering of dinosaurs.

Their fossils are fairly common, and skin impressions aren't uncommon. But what made this find stand out was that the entire three-dimensional skin envelope of the animal had been fossilized because it had died and been quickly buried in mineral-rich river sediments.

"It's a bit like finding cars for centuries and not knowing what was under the hood, and then finding a car with an engine," says Manning. "It's not an impression. It has actual structure, it's fossilized skin."

The fossil is so complete that scientists can estimate the muscle volume of the tail, says Manning.

The dinosaur discovery dates to 1999, when 17-year-old Tyler Lyson was on a fossil-hunting expedition near his family home in Marmarth, N.D., and he saw three tail vertebrae in a cliff. He thought that he'd found the very end of a tail and that the rest of the dinosaur had washed away eons ago.

But he went on to study paleontology in college, and when he came back in 2004 with a digging crew, he realized it was the other way around — only the end of the tail had fallen off, and the dinosaur itself was still embedded in the rock.