Trilobites (meaning three lobes in Latin) are a well-known fossil group of extinct marine arthropods. Trilobites roamed the ocean floors for over 270 million years, and went extinct about 250 million years ago.
This is a sculpted model, from fossils, of Kainops invius which Geologists - and Petro geologists - refer to as the index fossil of this period in our Earth's history. An arthropod is an invertebrate animal (just think spineless colleagues) having an exoskeleton, a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda which means jointed leg; and present day descendants include the insects, arachnids, crustaceans, and others. [chain not included]