Sea Cow Heritage (IMAGE) Duke University Caption Steven Heritage, a researcher at the Duke Lemur Center’s Museum of Natural History, holds the 33-million-year-old fossil mandible of an extinct sea cow which is related to modern manatees. Credit Catherine Riddle Usage Restrictions none License Original 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.