Denticle Family (IMAGE) University of California - Santa Barbara Caption Dillon was able to identify groups of sharks on the ancient reef based on the scales they left behind. Credit ERIN DILLON, ASHLEY DIEDENHOFEN, AND JORGE CEBALLOS Usage Restrictions For Use 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.