The trace fossil of the iguana burrow (IMAGE) Emory Health Sciences Caption Anthony Martin next to the trace fossil of the Pleistocene iguana burrow. Credit Photo by Melissa Hage. Usage Restrictions Must include credit. 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.