Dinosaurier

A partially mummified hadrosaur discovered by a teenager in North Dakota may be the most complete dinosaur ever found, with intact skin that shows evidence of stripes and perhaps soft tissue, researchers said on Monday.



Enough of the animal remains to show it ran quickly and was far more muscular than scientists believed such dinosaurs were.



"It's sort of King Tut meets T. Rex," paleontologist Phil Manning of the University of Manchester in Britain said in a telephone interview.



The creature is fossilized, with the skin and bone turned to stone. But unlike most dinosaur fossils, tissues are preserved as well.



This includes large expanses of the animal's skin, with clear remains of scales.



"This is not a skin impression. This is fossilized skin," Manning said. "When you run your hands over this dinosaur's skin, this is the closest you are going to get to touching a real dinosaur, ever."



The remains of the hadrosaur, dubbed Dakota, were found in 2000 by Tyler Lyson, then 17, on his uncle's ranch in North Dakota.



The hadrosaur, a plant-eating dinosaur that walked on two legs, lived 67 million years ago, during the late Cretaceous Period.



Lyson contacted Manning. The National Geographic Society, which helped pay for the expedition, will air a television program about the team's work on Sunday.



Manning had the team remove the monstrous specimen almost intact, with just the tail in a separate block.



It weighed close to 10,000 pounds (4,500 kilograms).



They persuaded the Boeing Company and NASA to use a huge computed tomography, or CT, scanner in Canoga Park, California, that is usually used to scan space shuttle parts.



LOOKING FOR THE HEAD



The dense fossil has taken months to scan, Manning said. "We will know in the next few days if the head is in there," he said.



The tail piece turned up some surprises. The animal's back end is 25 percent larger than previously thought.



Locomotor biologist Bill Sellers of the University of Manchester used a computer program to reconstruct how the hadrosaur would have moved and came up with a picture of an animal that walked not upright, but with its head low to the ground and forearms almost touching.



The strong muscles connecting its upper legs to its tail would have allowed it to run at speeds of up to 28 miles (45 km) an hour, well ahead of its predator, Tyrannosaurus rex.



Patterns in the scales resemble those associated with skin color changes in lizards. This provides the strongest evidence yet that the animal had stripes, Manning said.



The researchers are looking for preserved proteins. They have some results that have been offered to a scientific journal, Manning said.



"It's contentious. We say we are finding soft tissues where people previously have not looked," he said.



They also found a second fossil, one that Manning calls the "the hand of doom." The clawed foot belongs to a species of crocodile that may have been dining on Dakota soon after it died in a riverbed.



"It could have crawled up the back passage of the animal, went to get the guts and ended up stuck," Manning said.