Fossils in Paleozoic Chert Millstones. (IMAGE) American Geosciences Institute Caption This is a close-up of millstone at Black Hand Gorge, showing fusulinids in various views, scale bar 3 mm. Credit J.T. Hannibal et al.; SEPM (The Society for Sedimentary Geology) Usage Restrictions None 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.