Doushantuo Fossil (image) Virginia Tech Caption The photo (field of view about 0.15 millimeter in width) is of an exceptionally preserved eukaryotic fossil from the Doushantuo Formation (635-551 million years old) in South China. High-resolution geochemical data from the Doushantuo Formation indicate that the early diversification of eukaryotes may have coupled with episodic oxygenation of Ediacaran oceans. Credit Photograph by Shuhai Xiao Usage Restrictions with report of research reported in PNAS 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.