A newly analyzed fossil from Montana State University’s Museum of the Rockies provides unprecedented insight into Tyrannosaurus rex predatory behavior. The specimen, featuring a tyrannosaur tooth permanently embedded in an Edmontosaurus skull, represents a rare and significant find according to researchers from Montana State University and the University of Alberta.
Dating back 66 million years to the Late Cretaceous period, this fossil unveils a dramatic confrontation between apex predator and herbivore in what is now eastern Montana. The region was home to diverse dinosaur species, including the iconic Tyrannosaurus rex, the ceratopsian Triceratops, and the ornithopod Edmontosaurus.
An Exceptional Preserved Predator-Prey Interaction
In 2005, paleontologists discovered a near-complete Edmontosaurus skull in the Hell Creek Formation on Bureau of Land Management administered land. The fossil, now housed at the Museum of the Rockies, contains a remarkable feature: a broken tyrannosaur tooth lodged in the dinosaur’s facial region. This unique specimen became the focus of a comprehensive study led by University of Alberta doctoral candidate Taia Wyenberg-Henzler and Museum of the Rockies Curator John Scannella, with findings published in PeerJ.
“Embedded teeth in fossils are exceptionally rare, but finding one in a skull provides definitive evidence of both the victim and attacker,” explained Wyenberg-Henzler. “This specimen allows us to reconstruct a precise moment in Cretaceous ecosystem dynamics, similar to forensic analysis at a crime scene.”
Advanced Imaging Techniques Clarify Fossilized Encounter
Researchers employed meticulous tooth comparisons with known Hell Creek Formation theropods, confirming the predator as Tyrannosaurus. High-resolution CT scans conducted at Advanced Medical Imaging in Bozeman Health Deaconess Hospital revealed critical details about how the tooth became embedded during the prehistoric attack sequence.
“This fossil is extraordinary because it preserves a behavioral moment—a tyrannosaur biting into this duck-billed dinosaur’s face,” noted Scannella. “The absence of bone healing around the tooth suggests the Edmontosaurus was likely already deceased when the fatal bite occurred, or died as a direct result of the attack.”
Unprecedented Evidence Illuminates T. rex Hunting Tactics
The tooth’s placement in the Edmontosaurus nose area indicates a face-to-face confrontation, consistent with fatal predator-prey interactions. The substantial force required to break the tooth during insertion provides compelling evidence of Tyrannosaurus’ lethal hunting prowess. This rare preservation offers groundbreaking insights into one of the most debated aspects of T. rex ecology: its hunting strategies and feeding behavior.
