Scientists Get Rare Look at Dinosaur Soft Tissue
Monday, December 3, 2007
A high school student hunting fossils in the badlands of his native North Dakota discovered an extremely rare mummified dinosaur that includes not just bones but also seldom seen fossilized soft tissue such as skin and muscles, scientists will announce today.
The 25-foot-long hadrosaur found by Tyler Lyson in an ancient river flood plain in the dinosaur-rich Hell Creek Formation is apparently the most complete and best preserved of the half-dozen mummified dinosaurs unearthed since early in the last century, they said.
Much scientific investigation remains to be done, and no peer-reviewed studies of it have yet been published, but the discovery appears to be yielding tantalizing new clues about the size, body mechanics and appearance of the reptilian beasts that ruled the Earth millions of years ago, said paleontologists studying the specimen.
"He looks like a blow-up dinosaur in some parts," said Phillip Manning, a paleontologist at the University of Manchester in England who is leading the inquiry. "When you actually look at the detail of the skin, the scales themselves are three dimensional. . . . The arm is breathtaking. It's a three-dimensional arm, you can shake the dinosaur by the hand. It just defies logic that such a remarkable specimen could preserve."
Although it is described as "mummified," the 65 million-year-old duckbilled dinosaur that scientists have named Dakota bears no similarity to the leather-skinned human mummies retrieved from ancient tombs in Egypt. Time long ago transformed Dakota's soft tissue into mineralized rock, preserving it for the ages.
"It's a dinosaur that was turned into stone, essentially," said Lyson, 24, now a graduate student in paleontology at Yale University.
A lifelong dinosaur enthusiast, Lyson has been strapping on a backpack and hunting (and finding) dinosaur bones in the arid outback of his home state ever since elementary school. He even started an organization, the Marmarth Research Foundation ( http:/
On an expedition in 1999, Lyson noticed some bone fragments at the base of a hill and traced their origin to a point farther up. There he spotted three vertebrae from the tail of a hadrosaur, a common plant eater that traveled in herds and is sometimes described as the cow of the Cretaceous Period. A pretty good find, Lyson thought, but not outstanding. He marked the location in his notes and moved on.
But in 2004, after leading a team of amateur researchers in an excavation that did not pan out, a disappointed Lyson turned his attention again to the vertebrae he had left behind five years before.
"I didn't have very high hopes for the animal," Lyson said. "I figured the excavation would take two or three weeks, I'd have a hadrosaur tail, it would make a nice museum piece, but scientifically it would not be that impressive."
After finding a small piece of fossilized skin, however, Lyson knew he was onto something special. A friend at the dig knew Manning, and within months, Lyson and he had agreed to pursue the project.
They completed the excavation in summer 2006, removing a 10-ton block containing most of Dakota's body and a four-ton block with most of the tail. These were later whittled down to about four tons and less than a ton, respectively. Researchers are studying them with common tools such as tweezers but also with massive CT scanners at a facility near Los Angeles formerly used by NASA and Boeing.
Already, the scientists say they have made fascinating discoveries. The skin around the tail and on large swaths of the body appears generally in its original shape rather than squashed flat against the bones, giving researchers a three-dimensional look at Dakota. They can see both legs and arms and the chest cavity. The head and neck are not visible, but the researchers think they may be folded within the body block. They do not know whether the internal organs are there, nor have they determined the creature's sex, although they refer to it as a male.
The scientists have felt the scales near Dakota's elbow, noticing that they vary in size -- an indication, perhaps, of changes in skin color, texture or flexibility. They found a fleshy pad on its palm, an indication that it did not permanently walk on all fours, and keratin hooves on its feet.
The areas of uncollapsed skin have aided researchers in reconstructing Dakota's muscle sizes and allowed them to see, for instance, that a hadrosaur's backside was about 25 percent larger than previously thought. They estimate that Dakota could run as fast as 28 mph, faster than a Tyrannosaurus rex, the top predator of the time.
"It's almost as if we've geochemically preserved this dinosaur laboratory, and we've only just unlocked the door," said geochemist Roy Wogelius of the University of Manchester.
How Dakota perished is a mystery, but his death came near a river, and his body, curled in the fetal position, was quickly covered in water, wet sand and other sediment. The carcass was visited by at least one scavenger, a crocodile of the era that, Manning said, may have become stuck while feeding and died. Scientists found its preserved arm poking through Dakota's chest.
"It's a fossil within a fossil," Manning said. "We were over the moon when we found it."
Over time, weak acids in the sediment probably helped form the siderite, or iron carbonate, that encased both bodies and preserved them for millions of years, the researchers said.
Three experts said Dakota sounds like a potentially significant find, but they cautioned that there is no way to know until scientific studies are published. One expressed disappointment that the National Geographic Channel already plans to air a documentary about the case, "Dino Autopsy," Sunday, and that the team has already written two laymen's books (one for children) about it.
"It's never been published scientifically, and so it's all just hearsay," said paleontologist Jack Horner of Montana State University. "The job of a scientist is to be skeptical until evidence is presented. . . . We try not to put stuff out to the public before it's been peer-reviewed. Otherwise you get all kinds of crazy stuff out there."
The Dakota researchers have one scientific paper in peer-review now and two others nearly ready for submission, said Lyson, who expects one or more to be published in the next few months. He said the documentary merely walks viewers through the process of the science and shows them the excitement of it.
"We don't have many conclusions in there because that wasn't really the point of it," said Lyson, who plans to display Dakota someday in a nonprofit museum he is creating in Marmarth. "I totally agree that before we go out and say, 'Oh look, this is the greatest dinosaur ever, and it has showed us this and showed us that,' we have to prove it to the scientific community. We're still waiting on a lot of that."