This Specimen has been sold.
3.9" Crotalocephalina Trilobite With Zlichovaspis - Atchana, Morocco
This is a stunning association of two different types of trilobites from the Lhandar Formation near Atchana, Morocco. There is a large, 3.9" long Crotalocephalina gibbus naturally associated with a 2.8" long Zlichovaspis rugosa. They have been carefully prepared to remove the hard limestone surrounding the fossils leaving them in a spectacular pose.
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.