Another piece of evidence used by paleontologists to determine dinosaur diets are tooth marks. Most of the grooves or punctures found associated with fossilized dinosaur bones were the result of attacks by carnivorous dinosaurs. Most of the time, however, this evidence does not reveal whether the victim was actively hunted or scavenged—and except in certain cases, the identity of the predator cannot be determined.

In one instance, the spacing of the scoring found on the bones of an Apatosaurus, a herbivore, matched the spacing of teeth from the jaw of an Allosaurus, a carnivore. In another case, dental putty was used to make molds of puncture marks found in a Triceratops’s (an herbivore) pelvis, and an Edmontosaurus’s (another herbivore) phalanx. The resulting molds nicely matched the fossilized teeth of the perpetrator, a carnivorous Tyrannosaurus. In one rare instance, a Tyrannosaurus tooth was found stuck in the fibula of an herbivorous hadrosaur, Hypacrosaurus. Of course, in the most obvious cases (and the most rare), predators could be identified if the fossil bones—and teeth—of the two animals were locked in mortal combat.