Bring Out Your Sead (IMAGE) University of Chicago Caption Susan Kidwell explains how studies of molluscs -- clams and snail -- can be used for ecological assessments in the Proceedings of the National Academy of Sciences. Credit Photo courtesy of Susan Kidwell Usage Restrictions This photo may be used by news organizations in reports describing the research of Susan Kidwell. 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.