This is a pair of rare US trilobites. These are Genevievella granulatus (right) and Coosella sp. from the Upper Cambrian of Utah. Genevievella has a large head, a small tail, and a pustulous thorax. There is a long spine that eminates off of the seventh axial ring that lays on the axial lobe of the tail - this specimen showcases this spine in wonderful fashion. The Coosella is enrolled, which is quite unusual. Both trilobites have good natural color and contrast well with the striking red matrix. This is a very fine association of two elusive Weeks trilobites.
Note: This specimen was obtained legally. However, normally it is illegal to sell fossils from the Weeks Formation and other BLM land.