Ivory study image 1 (IMAGE) University of Bristol Caption A selection of elephant and mammoth tusk samples Credit Ben Booth Usage Restrictions The image tmust only be used to illustrate this study and must not be used for commercial purposes 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.