50 Million-Year-Old Fossil Cricket from a Green River Formation Fossil Site in Colorado (image) National Evolutionary Synthesis Center (NESCent) Share Print E-Mail Caption Fine-grained lake sediment covered and buried the animals that lived in the Green River Formation, preserving them in exquisite detail. Credit Specimen number 45545 from the University of Colorado Museum; Photo courtesy of Dena Smith. Usage Restrictions None 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.