The group of ferocious meat-eating dinosaurs known as tyrannosaurs—of which the most famous member is Tyrannosaurus rex—may have sometimes turned their sharp teeth on each other. A distinctive pattern of tooth marks on the skull and jaw of a tyrannosaur discovered at Dinosaur Provincial Park in Alberta, Canada, offers the best evidence of that yet, scientists say. The dinosaur, known as Daspletosaurus (pictured above in a fight with a fellow dino), was not fully adult when it died, but still weighed about 500 kilograms and was almost 6 meters long—just a tad smaller than T. rex. Daspletosaurus lived about 75 million years ago, nearly 10 million years before T. rex. In a study published online this week in PeerJ, the researchers conclude from both the spacing and shape of the puncture marks on its skull that it was bitten by another tyrannosaur—quite possibly another Daspletosaurus—while it was still alive, probably as the result of a dino-on-dino fight. Those wounds healed, but tooth marks on its jaw suggest that the meat eater was chomped on by yet another tyrannosaur after it died.