What are arthropods?

The Phylum Arthropoda has more species and wider distribution than any other phylum. Excluding insects, the group includes horseshoe crabs, spiders, scorpions, daphnia, shrimps, crabs, centipedes, millipedes, and barnacles. Arthropods have segmented bodies and some of the segments fuse to form body zones. The appendages are segments and are connected to the body by joints.