T. rex Left Its Teeth in Wyoming Bone — But Not My Wyoming

A paper out this month catalogs tyrannosaur bite marks on dinosaur bone from Wyoming — and in a companion find, an Edmontosaurus skull turned up with a T. rex tooth still lodged in the face. Rare, vivid evidence of a predator meeting its prey.

People hear “Wyoming dinosaurs” and assume it’s all one story. It isn’t, and this is a good chance to say why. The animals I helped excavate at Shell came out of the Morrison Formation — Late Jurassic, roughly 150 million years old. T. rex belongs to the Late Cretaceous, about 66 million years ago, out of rock like the Lance and Hell Creek. That’s an 85-million-year gap sitting in the same state. There were no tyrannosaurs in my quarries — the Jurassic had its own top predators.

I know that firsthand: at the Shell sites we recovered Allosaurus and Torvosaurus teeth alongside the sauropods and the stegosaur. Different cast, same role. When you read “bite marks in Wyoming,” it’s worth asking which Wyoming — the rock underfoot changes the animal by tens of millions of years.

Source: reporting on a July 2026 study in PLOS One. Read the original for the specifics.