| Outcrops of the late middle Ordovovician Antelope Valley Limestone in Eureka County, Nevada (hills in middle distance), a number of miles west of the western border with White Pine County, Nevada; capping the hills is the upper Ordovician Eureka Quartzite. The Antelope Valley geologic rock unit yields a wide assortment of paleontologic material, including: trilobites, brachiopods, ostracods, bryozoans, conodonts, gastropods, sponges, Receptaculites (an extinct green algae), and early echinoderms. Photograph courtesy Rachel Dolbier, Daniel M. Sturmer, Thomas Anderson, and Regina N. Tempel; I edited and processed the image through photoshop. |