23" Cluster Of Ordovician Trilobites (Sokhretia?) - Erfoud, Morocco
This is a beautiful, cluster of sixteen Sokhretia trilobites from Tisserdmine near Erfoud, Morocco. These appear to be the same species as Sokhretia solitaria described from Czechoslovakia. The trilobites average just over 2 inches in length and are nicely inflated. It is a natural association on a thick, 23 x 16.5" chunk of limestone.
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.