As unlikely as it seems, the fossilized remains of an 80-million-year-old dinosaur can still contain bits of soft tissue and fragments of proteins.
Mary H. Schweitzer, a vertebrate paleontologist at North Carolina State University in Raleigh, and her colleagues report in the May 1 Science that they’ve recovered flexible tissue from the 80-million-year-old fossil femur of a plant-eating dinosaur called a hadrosaur. The tissue resembles collagen from the demineralized bones of modern-day birds — a group that many paleontologists consider to be closely related to dinosaurs.
In 2005, Schweitzer and several of the same colleagues announced similar results with a 68-million-year-old Tyrannosaurus rex (SN: 3/26/05, p. 195). Subsequent chemical analyses suggested that those fossils included fragments of collagen protein (SN: 4/14/07, p. 228).
The new analyses, which include tests beyond those previously reported for the T. rex fossils, also suggest that the hadrosaur fossil contains fragments of elastin and laminin — which, like collagen, are extracellular proteins found in soft tissues.
The precise recipe of environmental conditions that lead to such molecular preservation is still a mystery, Schweitzer says. However, she notes, the team’s research suggests that the sudden burial of a dinosaur carcass in a porous, sandy material seems be one key to such exceptional fossilization.