# T. rex bite marks discovered on duck-billed dinosaur fossils 72-million-year-old fossils shed light on dinosaur feeding behaviors. - **Source:** [Popular Science](https://brifing.si/source/cc3d313a-759c-4802-b881-fc8585f35ef9) - **Published:** 2026-07-15 - **Topic:** [Business](https://brifing.si/c/business) - **Original article:** - **On Brifing:** https://brifing.si/s/09779d2c-f240-4004-8f00-92b7ce2cc735 ## A prehistoric hunting scene Among 3,000+ fossil bones found in Wyoming, researchers identified 12 with bite marks likely from T. rex. This discovery reveals a hunting scene from 72-66 million years ago. ## The fate of Edmontosaurus Most bite-marked bones belonged to duck-billed Edmontosaurus annectens. These large herbivores were likely prime prey for T. rex during the Late Cretaceous period. ## Secrets in the bite marks Researchers analyzed tooth mark spacing and shape to identify T. rex as the biter. Lack of healing signs suggests bites occurred at or after death, indicating predation or scavenging. ## Paleontological detective work The study provides a guide for identifying tooth marks on fossils, helping distinguish them from marks caused by joint disease or erosion - crucial for accurate prehistoric behavioral studies. ## Traces of prehistoric ecosystems Bite marks offer critical insights into dinosaur feeding behaviors and species interactions. These findings help reconstruct Late Cretaceous ecosystems with greater accuracy. ## Treasures beneath our feet Researchers emphasize many more fossils await discovery underground. Each new find deepens our understanding of the dinosaur world and its complex food chains. ## Sources covering this story - https://www.popsci.com/science/t-rex-teeth-marks-dinosour-bones/ — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._