The term Trilobite refers to an extinct class of arthropods. Tri-lobe0ite alludes to the three-part, longitudinal division of their exoskeleton. These animals first appeared at the beginning of the Cambrian Period around 570 million years ago. They flourished throughout the early Paleozoic Era and then decreased in diversity until their extinction in the late Permian Period around 240 million years ago.

These marine invertebrates were primarily bottom dwellers. Fossilized remains of trilobites have been found on every continent and admired by humankind, considered objects of value for thousands of years. In the town of Dudley, England, the "Dudley Locust", an Ordovician trilobite of the genus Calymene, has been collected and sold in shops since the 17th century. Today Trilobites are prized by collectors and museums throughout the world as objects of beauty and curiosity. Scientists use Trilobites as stratigraphic index fossils which help to determine the age of rock formations.

The true value of trilobites, however, lies in the fascinating story which these fossils tell about the history of ancient life on Earth. Age: Early Cambrian Location: Djbel Ougrat, Morocco