This Specimen has been sold.
2.3" Detailed Hollardops Trilobite - Multi-Toned Shell
This is a detailed, 2.3" long Hollardops mesocristata trilobite fossil quarried near Ofaten, Morocco. Nice eye facet preservation it both eyes with good preparation. The multi-toned shell coloration is natural and something often seen on trilobite fossils from this location. It's due to part of the trilobite being closer to a fault in the rock. Groundwater or hydrothermal fluids running through this fault leached minerals from the shell changing it's color. There is a little bit of missing shell along repaired cracks.
Trilobites were a very diverse group of extinct marine arthropods. They first appeared in the fossil record in the Early Cambrian (521 million years ago) and went extinct during the Permian mass extinction (250 million years ago). They were one of the most successful of the early animals on our planet with over 25k currently described species, filling nearly every evolutionary niche. Due in large part to a hard exoskeleton (shell), they left an excellent fossil record.