California Mesonacis fremonti Trilobite

Mesonacis fremonti was a genus of trilobite that has had a long presence in the fossil record. This one was excavated at the world famous California Marble Mountains site, located in the Mojave Desert. It is from an old collection. The genus is impressive, robust looking, and could grow to an impressive size. This one is centered on a small piece of muted purple shale. The matrix has the typical fine-grained, fractured look of the Latham Shale beds. It was professional prepared using air abrasion. Trilobites from this formation are rarely found fully intact.