| Top and bottom: Top--Sand Dollar from the Middle Pliocene San Joaquin Formation, North Dome area, Kettleman Hills, California. Called scientifically, Astrodapsis arnoldi fresnoensis. Bottom--Sand Dollar from the Lower Pliocene Etchegoin Formtion, Kettleman Hills, California. Called scientifically, Dendraster gibbsii. Photographs by Sheila Steiner (top) and Costas Soler (bottom), courtesy Copyright © 2017 University of California Museum of Paleontology; images used per parameters provided by the Creative Commons license. I edited and processed the photo through photoshop. |