Whale Bone Fossil (IMAGE) Smithsonian Caption Whale bone fossil showing three tooth marks from a shark. The marks on the rib indicate the whale was once severely bitten by a strong-jawed animal. Judging by the 6 centimeter (2.4 inch) spacing between tooth marks, scientists believe the attacker was a mega toothed shark Carcharocles megalodon, or perhaps another species of large shark which was alive at that time. The whale appears to have been an ancestor of a great blue or humpback. Credit Photo by Stephen Godfrey Usage Restrictions Please include the photo credit when using. 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.