| The grayish specimens embedded in the orange-brown matrix are natural cross-sections of fusulinids, the wheat to football-shaped shells secreted by an exinct single-celled animal, from the Lower Permian Owens Valley Group, Inyo County, California. Most likely, the fusulinids can be assigned to the genera Schwagerina, Pseudoschwagerina and Parafusulina. The elongated remains are natural cross-sections along the length of the shell; oval to circular specimens represent fusulinids that have, essentially, been sawed in half by the processes of erosion, revealing their internal structure from an end-on perspective. |