Proterozoic Fossil Record (IMAGE) Georgia Institute of Technology Caption Earliest animals evolved in the mid to late Proterozoic Eon and lie deep in the fossil record. Credit Douglas Erwin / National Museum of Natural History Usage Restrictions Please give special attention to the photo credit, as it is from a participating researcher not from Georgia Tech. It may not be used in connection with other stories about Georgia Tech. 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.