What Does a Tyrannosaur Tooth Still Lodged in a Dinosaur's Face Prove?

The Fossil That Froze a Predatory Strike in Time

A tyrannosaur tooth found lodged inside the nasal bone of an Edmontosaurus skull — catalogued as MOR 1627 — provides direct, physical evidence of a face-to-face predatory attack that took place approximately sixty-six million years ago in what is now Montana.

What Is MOR 1627 and Where Was It Found?

MOR 1627 is the museum catalogue number for an Edmontosaurus skull recovered from the Hell Creek Formation of Montana, one of the most productive and studied fossil sites in the world. The Hell Creek Formation dates to the very end of the Cretaceous period, just before the mass extinction event that wiped out non-avian dinosaurs. It has yielded remains of Tyrannosaurus rex, Triceratops, and dozens of other species, making it a critical window into the final chapter of the Age of Dinosaurs.

Edmontosaurus was a hadrosaur — a duckbilled dinosaur — that could reach lengths approaching forty feet. It was a large herbivore and almost certainly a prey animal for large tyrannosaurs sharing its environment.

How Did the Tooth End Up Inside the Bone?

The broken tyrannosaur tooth is embedded in the nasal region of the Edmontosaurus skull — the face. That specific location is significant. A bite to the face suggests a direct, frontal encounter rather than an attack from behind or to the flank. The tyrannosaur and the Edmontosaurus were, in that moment, facing each other.

Tyrannosaurs were well known for shedding and replacing teeth continuously throughout their lives, much like sharks. Losing a tooth during a powerful bite was biologically trivial for the predator. But in this case, the tooth snapped and remained embedded in the bone of its prey.

What Does the Lack of Healing Tell Scientists?

This is where the fossil becomes especially powerful as evidence. When an animal survives an injury, bone tissue responds. It begins to remodel, grow, and close around the wound. That biological response leaves visible traces that paleontologists can identify and interpret.

The bone surrounding the embedded tooth in MOR 1627 shows no healing whatsoever. There is no reactive bone growth. No remodeling. Nothing. That absence is a statement: the Edmontosaurus did not survive long after this bite. The encounter recorded in this skull was almost certainly fatal, or at minimum the animal died very shortly after the strike occurred.

Why Does This Single Fossil Matter to Paleontology?

Most of what we know about predator-prey interactions in the fossil record is inferred — from bite marks on bone, from trackways, from tooth shape and body mechanics. Direct physical evidence of a specific attack, frozen at the moment of impact, is extraordinarily rare.

MOR 1627 is not a reconstruction or a hypothesis. It is an unaltered record of a single event: one tyrannosaur biting one Edmontosaurus in the face, sixty-six million years ago. The tooth stayed. The bone preserved it. And millions of years later, paleontologists pulled it from the ground in Montana — the predator’s tooth still locked inside its prey.

Few fossils in the world capture a single moment in time with this level of precision and clarity.