Facivermis (IMAGE) University of Exeter Caption Mystery has long surrounded the evolution of Facivermis, a worm-like creature that lived approximately 518 million years ago in the Cambrian period. Credit Franz Anthony Usage Restrictions This image may only be used with reports of this research 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.