Injuries inflicted on a tyrannosaurus in life appear to be inflicted by another tyrannosaurus. But a new research paper reports similar injuries on another t-rex skull inflicted after death, suggesting that tyrannosaurus scavenged its own kind.
There is no evidence that the animal died at the hands (or mouth) of another tyrannosaur. However, the preservation of the skull and other bones, and damage to the jaw bones show that after the specimen began to decay, a large tyrannosaur (possibly of the same species) bit into the animal and presumably ate at least part of it. Combat between large carnivorous dinosaurs is already known and there is already evidence for cannibalism in various groups, including tyrannosaurs. This is however an apparently unique record with evidence of both pre- and post-mortem injuries to a single individual.