Two Fossil Early Synapsids (IMAGE) Proceedings of the National Academy of Sciences Caption Two fossil early synapsids. On the left is a pelycosaur (Ophiacodon FMNHPR454) and on the right is a therapsid (Procynosuchus FMNHPR4974). Credit Image courtesy of Jacqueline K. Lungmus. Usage Restrictions None 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.