Tyrannosaurs were cannibals

New York: A recently unearthed tyrannosaur bone has revealed a nasty little 66-million-year-old family secret that T.Rex were not shy about eating their own kind, say researchers.

The bone has peculiar teeth marks that strongly suggest it was gnawed by another tyrannosaur. The grooves were clearly those of an animal pulling the flesh off the bone.

The researchers found that one groove 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. Serrated teeth rule out crocodiles and point directly to a theropod dinosaur like T. rex.

The fact that the only large theropods found in the Lance Formation are two tyrannosaurs --Tyrannosaurus rex or Nanotyrannus lancensis -- eliminates all interpretations but cannibalism, McLain explained.

However, the bones do not reveal whether the cannibal was scavenging or was also the killer of the tyrannosaur, the researchers said.