Tyrannosaurus Rex’s reputation as a fearsome predator got a critical vindication this week, with an excavated tooth found stuck in the fossilized remains of another dinosaur that apparently suffered a bite from the T-Rex but managed to escape. According to its discoverers, the finding offers proof that this big-jawed, tiny-armed prehistoric meat-eater really did hunt its prey—and that it wasn’t, as some paleontologists have been arguing, just a scavenger.
A team of fossil researchers found the tooth and the plucky survivor —which they identified as a Hadrosaurus, one of the dinosaur era’s “duck-billed” dinosaurs, who walked on two legs and had bony snouts that they used to forage for plant matter—at North Dakota’s “Hell Creek” fossil site. Robert DePalma of the Palm Beach Museum of Natural History, in Fort Lauderdale, led the expedition.
According to the report that DePalma and colleagues published Monday in the journal Proceedings of the National Academy of Sciences, the team unearthed the Hadrosaur fossil and then noticed a 1.5-inches-long T-Rex tooth lodged in the Hadrosaurus’s tail—permanently stuck there from a bite, the team inferred. In the journal report, DePalma et al. call this “conclusive” proof that T-Rex attacked and killed other dinosaurs for its everyday sustenance.
The notion sounds like common knowledge to school kids everywhere, who have been raised for generations to imagine the T-Rex’s of old tearing after other dinosaurs in the land before time. But not so among paleontologists: In 2011, acclaimed paleontologist John “Jack” Horner” and co-authors argued, based on 12 years of studying T-Rex remains in Montana, that the large numbers of T-Rexes in the area suggested that the beast was more of a forager than a hunter. Also, Horner said, the T-Rex’s body structure suggested that while it had a sharp sense of smell and bone-crushing teeth, it wasn’t a fast runner—three characteristics that would have suited it well for searching after dead and dying animals to eat, as opposed to chasing after live ones.
This Hadrosaurus that DePalma and his team found, however, looks to have been very much alive at the time of the bite—and furthermore, it stayed alive for a lengthy period of time after. All things considered, this seems to put a nail—er, tooth—in the coffin of lingering doubts over T-Rex’s hunting prowess.
That the Hadrosaurus got away doesn’t belittle T-Rex’s hunting capacities, either, incidentally. Present-day wolves, lions, and other large carnivores lose their prey 45% to 62% of the time, DePalma and colleagues’ study also noted.