Tyrannosaurus rex: Cannibal?

From the Times On-Line:

The most famous dinosaur of all, Tyrannosaurus rex, may have been a cannibal. The American fossil hunter Mike Triebold recently uncovered the fossil of a juvenile T. rex scored with the fang marks of an adult Tyrannosaurus. Triebold declares, in National Geographic, this to be “the first direct evidence of rex-on-rex violence”.

In addition, the Montana site contained teeth from Nanotyrannus, a smaller, closely related species. Triebold speculates that the youngster may have been slaughtered and partially eaten by the older T. rex, with the so-called 'Nanos' finishing the scraps. But there are alternatives — a pack of 'Nanos' may have committed the murderous deed, with the older T. rex finishing the remains. Or the rex-on-rex fatal fang fight may have been territorial rather than cannibalistic. Still, it will add to the fledgeling debate about whether dinosaurs were Cretaceous cannibals. The gruesome practice is, of course, well documented in several mammalian species, including humans.