Robert Foley, University of Cambridge (IMAGE) University of Cambridge Caption This is Prof. Robert Foley recording lithic density on the Messak. Credit Foley/Mirazón Lahr Usage Restrictions Please 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.