Trilobite Fossils

Trilobites are extinct marine arthropods of the class Trilobita that look much like modern horseshoe crabs. Trilobites are one of the earliest groups of arthropods, dating from the Early Cambrian to the Devonian (about 520 to 360 million years ago), although smaller numbers survived until the end of the Permian (250 mya).

Like modern arthropods, trilobites had a hard exoskeleton and molted as they grew. As a result, great numbers of trilobite shell fragments can be found, but entire specimens are rare, making even a good cephalon a nice find. Trilobites can be found in a couple of places around Las Vegas. The closest is the base of Frenchman Mountain on the east side of the Las Vegas Valley. Most of the material here is fragmentary, but it is close to town. Trilobites can also be found near Cadiz and Chambless, California south of Las Vegas, the Nopah Quarry just west of Emigrant Pass on the Old Spanish Trail highway southwest of Pahrump, and the Oak Springs Trilobite Quarry up towards Caliente. These sites are on BLM land where collecting small amounts for personal use is legal.