This Specimen has been sold.
Cyphaspis & Enrolled Diademaproetus Trilobite Association
This is a nice, natural association of two different types of trilobites from Foum Zguid, Morocco. There is a nicely prepared Cyphaspis eberhardiei is about 1.6" long including the spines right next to an enrolled Diademaproetus mohamedi. All of the spines have been prepared free standing and there isn't any restoration.
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.