1.5" Spiny Cyphaspis Trilobite
This is an nicely prepared, 1.5" long (including spine) Cyphaspis trilobite from Morocco. It has very nice shell detail and preparation. The spines were left partially embedded in the limestone instead of free-stood as is often done with this 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.