Fossil samples (IMAGE) Geological Society of America Caption On the right, a slab of gray shale sample. Two black boxes mark places where fossilized algae are present; those are shown on the left. The fossils are reddish-brown marks, curving and broken into segments, on a gray rock background. Credit Photo by K. Maloney. Usage Restrictions Photo by K. Maloney. 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.