Stromatoporoids (IMAGE) Osaka Metropolitan University Caption Alternating layers of stromatoporoids (black to dark gray) and Chaetetes (light gray) in an upwardly convex structure Credit Osaka Metropolitan University Usage Restrictions News organizations may use or redistribute this image, with proper attribution, as part of news coverage of this paper only. 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.