Pliocene shells (IMAGE) University of Kansas Caption A picture of Pliocene (approximately 3 million years old) fossil mollusks as discovered out in the field in Florida. Credit Jonathan Hendricks, Paleontological Research Institute. Usage Restrictions None 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.