A fossilized Edmontosaurus skull unearthed in 2005 from Montana's Hell Creek Formation has yielded rare direct evidence of a Tyrannosaurus rex attack: a broken tyrannosaur tooth lodged in the plant-eater's snout, alongside up to 23 additional bite marks across the skull.
CT scans performed at Bozeman Health Deaconess Hospital show the tooth embedded in the dinosaur's nose, indicating the two animals met face to face. The wound shows no signs of healing, suggesting the encounter proved fatal. Researchers Taia Wyenberg-Henzler of the University of Alberta and John Scannella of the Museum of the Rockies led the study, published this week in the journal PeerJ.
"The great thing about an embedded tooth is it gives you the identity of not only who was bitten but also who did the biting," Wyenberg-Henzler said. The roughly 66-million-year-old specimen, now on display at the Museum of the Rockies in Montana, offers one of the clearest windows yet into how Tyrannosaurus hunted its prey.