<i>T. rex</i> Tooth Marks (IMAGE) Yale University Caption T. rex was the only big carnivore in western North America 65 million years ago that was capable of making such large gouges, such as the ones seen here on a toe bone. Credit Nicholas Longrich/Yale University Usage Restrictions With credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.