Fossil Species (image) George Washington University Share Print E-Mail Caption Each blue rectangle shows the range of a hypothetical fossil species, with an origination and extinction date. The red highlighted box shows a cluster of originations that occur at about the same time. Credit W. Andrew Barr Usage Restrictions With appropriate credit Share Print E-Mail 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.