This is a very nice, 2.3" long (if outstretched)" long Saharops bensaidi trilobite quarried at Oued Ghris, Morocco. The preservation and preparation on this specimen is fantastic. It has much better shell detail than most of the trilobites from this locality and the eye facets are clear in both eyes. Genal spines and around the edge of the head have been prepared free of the surrounding limestone. A fantastic specimen of a fairly scarce species.
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 described species, filling nearly every evolutionary niche. Due in large part to a hard exoskeleton (shell), they left a excellent fossil record.