Trilobite fossils in Utah shale

This is an Elrathia Kingi trilobite from the House Range in Millard County, Utah. This specimen features a complete trilobite measuring just over an inch long on one side, and parts of others on the back - see pix, preserved in the Utah shale from which they were harvested. The specimen you would receive will be exactly the one pictured. See pictures for dimensions and more details. Trilobites are a well-known fossil group, probably the second best known fossil group in the world (behind dinosaurs). These are from the mid- Cambrian period about 550 million years ago. As a species, trilobites disappeared from earth in a mass extinction event at the end of the Permian period about 250 million years ago.