To paleontologists, the news was only slightly less startling than if someone had spotted a live Apatosaurus stomping around the bayous of Louisiana. Last March Mary Schweitzer of North Carolina State University reported that she had extracted soft tissue from the 68-million-year-old fossilized femur of a Tyrannosaurus rex. Her finding, if confirmed, overthrows every grade school textbook’s explanation that fossils result from the mineralization of bone and the destruction of soft tissue. It also opens staggering possibilities. If tissue proteins can survive for millions of years, scientists could analyze them to make detailed interpretations of the biology of ancient species and their relationship to those living today.
The discovery happened after Schweitzer and a lab technician, Jennifer Wittmeyer, had soaked some T. rex bone in a solution so they could cut it into slices. “She came running in and said, ‘You’re not going to believe what has happened!’ ” Schweitzer recalls. “She went to pick up a chunk of bone we had demineralized, and it was stretchy. A few weeks later, we set up the experiment as before, and it happened again. We have a little movie of our tweezers stretching the material. You can see the blood vessels flexing inside.”
Schweitzer soon extracted similar stretchy vessels from two other tyrannosaurs and found hints of preserved bone cells in a duck-billed dinosaur. She is now analyzing the soft material to determine its composition and, above all, to see if it contains intact biological molecules. She is also trying to figure out how the T. rex fossil, unearthed from the Hell Creek Formation in Montana, could have retained a semblance of its original texture and chemistry. “We’ve got to get out into the field to figure out if there is something in this environment that might give us that information,” she says.
