Study links rare Wyoming bone bite marks to Tyrannosaurus rex feeding habits
Researchers analyzing over 3,000 Cretaceous fossils from Wyoming identified twelve bones with possible tooth marks, four of which match the spacing of T. rex teeth.
In a July 15, 2026 paper in PLOS One, scientists led by Bethania C. T. Siviero of Loma Linda University reported a systematic survey of more than 3,000 late-Cretaceous bones recovered from the Lance Formation in northeastern Wyoming. While the majority of the fossils belong to the herbivorous Edmontosaurus annectens, twelve displayed depressions, punctures or grooves that could be dental in origin. Four of these bones exhibited tooth-mark patterns that closely align with the expected shape and spacing of Tyrannosaurus rex teeth, leading the authors to attribute them to the apex predator.
The lack of bone healing around the marks implies the bites happened shortly before or after the animals died, supporting scenarios of predation followed by scavenging. To aid future work, the team compiled criteria for separating genuine bite marks from post-mortem alterations caused by disease, insects or erosion. Funding for the project came from internal sources at Loma Linda University.
Why it matters
The findings provide rare direct evidence of how T. rex interacted with prey, enriching our understanding of ancient ecosystems.
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