What is the function of the arthropod exoskeleton? What is the function of the arthropod exoskeleton? The presence of an exoskeleton has given arthropods a good fossil record, because hard parts fossilize more readily than do soft tissues. It makes growth by molting possible. It provides protection and functions in locomotion. It has no well-established function. (Trilobites had an exoskeleton, and they went extinct.)