what does arthropod mean
An arthropod (from Greek arthro- , joint + podos, foot) is an invertebrate animal having an exoskeleton (external skeleton), a segmented body, and jointed appendages. Arthropods form the phylum Arthropoda, and include the insects, arachnids, myriapods, and crustaceans. Myriapods comprise millipedes, centipedes, and their relatives and have many body segments, each bearing one or two pairs of legs. 2  They are sometimes grouped with the hexapods. 3  Crustaceans are primarily aquatic (a notable exception being woodlice) and are characterised by having biramous appendages.