Any member of the large animal clade, Arthropoda. Living lineages include crustaceans, arachnids, centipedes, millipedes, and insects. Fossil lineages include the extinct trilobites. All arthropods have a hard exoskeleton that is periodically shed during growth, a body that is divided into segments, and jointed legs. These traits were inherited from the common ancestor of all arthropods.
→ → arthropod