Fossil Reveals Tyrannosaurus Hunting Tactics

Embedded tooth in Edmontosaurus skull offers rare insight into dinosaur predator-prey interactions.

Published on Mar. 6, 2026

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A fossil on display at Montana State University's Museum of the Rockies reveals how dinosaurs in the Tyrannosaurus genus may have subdued prey. The specimen is the focus of a new collaborative research publication between scientists at MSU and the University of Alberta in Canada. The fossil shows an embedded Tyrannosaurus tooth in the skull of an Edmontosaurus, providing a rare glimpse into the hunting behaviors of the giant carnivorous dinosaur.

Why it matters

The feeding habits of Tyrannosaurus, one of the largest meat-eating animals to ever walk the Earth, have been the subject of study and debate for decades. This fossil provides a unique opportunity to better understand how Tyrannosaurus may have hunted and killed its prey, offering valuable insights into the predator-prey dynamics of the Late Cretaceous period.

The details

In 2005, a nearly complete Edmontosaurus skull was found in the Hell Creek Formation of eastern Montana. Lodged inside the Edmontosaurus' face is the tooth of a Tyrannosaurus. Comparing the embedded tooth to the carnivorous inhabitants in the Hell Creek Formation revealed that it most closely matched the teeth of Tyrannosaurus. CT scans of the skull helped provide greater detail, suggesting the Edmontosaurus met its attacker face-to-face and that the amount of force necessary for the tooth to become embedded in the bone points to the use of deadly force by the Tyrannosaurus.

  • In 2005, the Edmontosaurus skull was found in the Hell Creek Formation of eastern Montana.
  • The collaborative research publication was published in 2026.

The players

Taia Wyenberg-Henzler

A doctoral student at the University of Alberta who collaborated on the research.

John Scannella

The Curator of Paleontology at the Museum of the Rockies who collaborated on the research.

Tyrannosaurus

A giant carnivorous dinosaur that roamed the region that is now Montana at the end of the Age of Dinosaurs, about 66 million years ago.

Edmontosaurus

A plant-eating dinosaur that lived alongside Tyrannosaurus in the Late Cretaceous period.

Montana State University's Museum of the Rockies

The museum where the Edmontosaurus skull fossil is on display.

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What they’re saying

“Although bite marks on bones are relatively common, finding an embedded tooth is extremely rare. The great thing about an embedded tooth, particularly in a skull, is it gives you the identity of not only who was bitten but also who did the biting. This allowed us to paint a picture of what happened to this Edmontosaurus, kind of like Cretaceous crime scene investigators.”

— Taia Wyenberg-Henzler, Doctoral student, University of Alberta (PeerJ)

“A fossil like this is extra exciting because it captures a behavior: a tyrannosaur biting into this duckbill's face. The skull shows no signs of healing around the tyrannosaur tooth, so it may have already been dead when it was bitten, or it may be dead because it was bitten.”

— John Scannella, Curator of Paleontology, Museum of the Rockies (PeerJ)

“Looking at the way the tooth is embedded in the nose of the Edmontosaurus suggests that it met its attacker face-to-face, something that usually happens to an animal that was killed by a predator. The amount of force necessary for a tooth to have become broken off in bone also points to the use of deadly force. For me, this paints a terrifying picture of the last moments of this Edmontosaurus.”

— Taia Wyenberg-Henzler, Doctoral student, University of Alberta (PeerJ)

What’s next

The researchers plan to continue studying the fossil and other evidence to further understand the hunting behaviors of Tyrannosaurus and its interactions with other dinosaurs from the Late Cretaceous period.

The takeaway

This rare fossil provides a unique window into the predator-prey dynamics of the Tyrannosaurus and its prey, offering valuable insights that could help scientists better understand the evolution and behavior of one of the most iconic dinosaurs to have ever walked the Earth.