Proterozoic Eon (IMAGE) Virginia Tech Caption The simplified summary diagram shows the relative diversity of eukaryotic fossils throughout the Proterozoic Eon. Credit Graphic courtesy of Qing Tang of Nanjing University and Shuhai Xiao of Virginia Tech. Usage Restrictions Must credit 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.