Landry holding gray wolf skull (IMAGE) Canadian Museum of Nature Caption Zoe Landry, lead author of the study, holds a 40,000-year-old gray wolf skull from the Yukon. It was among the specimens analysed for the research project that determined the shift in diet over time of gray wolves. Credit Danielle Fraser © Canadian Museum of Nature. Usage Restrictions For use with the story about the gray wolf diet. 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.