This trilobite is Elrathia marjumi from the Middle Cambrian of Utah. This trilobite should not be confused with the more common Elrathia kingi from the Wheeler Formation. The trilobite is HUGE for this type - 1 3/4 inches long! It is very nicely articulated, and both free cheeks are present and tightly attached. The fossil has great detail and fabulous color and contrast. This is a collectible example of this unusual species of Elrathia.