A nasty little 66-million-year-old family secret has been leaked by a recently unearthed tyrannosaur bone. The bone has peculiar teeth marks that strongly suggest it was gnawed by another tyrannosaur. The find could be some of the best evidence yet that tyrannosaurs were not shy about eating their own kind.
"We were out in Wyoming digging up dinosaurs in the Lance Formation," said paleontologist Matthew McLain of Loma Linda University in California. "Someone found a tyrannosaur bone that was broken at both ends. It was covered in grooves. They were very deep grooves."
The grooves were clearly those of an animal pulling the flesh off the bone -- pulling in a direction perpendicular to the bone, in the same way humans eat a piece of fried chicken. But one groove stood out. It was located at the larger end of the bone and contained smaller parallel grooves caused by the diner's head turning, so that the serrated edges of its teeth dragged across the bone.