Bargain, 2" Trilobite (Paralejurus spatuliformis?) Fossil - Morocco
This is a 2" long Corynexochida trilobite which I believe is an example of Paralejurus spatuliformis, a fairly unusual type of Paralejurus. The pygidium is significantly different than that of the more common species of Paralejurus, being more similar to that of the genus Metascutellum.
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.