Trilobite fossil, Elrathia King Utah

These are Elrathia Kingi trilobites from the House Range in Millard County, Utah. The specimens pictured are exactly the pieces you would receive based on your sellection. Trilobites are a well-known fossil group, probably the second best known fossil group in the world (behind dinosaurs). These Utah specimens 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. Trilobites were a group of Arthropods, segmented bodies and limbs, with hard shells. Extinct today, over 15000 species have been classified to date, ranging in size from 1mm - 700mm long