The jaw is either of the two opposable structures forming, or near the entrance to, the mouth. The term jaws is also broadly applied to the whole of the structures constituting the vault of the mouth and serving to open and close it and is part of the body plan of most animals. Arthropods In arthropods, the jaws are chitinous and oppose laterally, and may consist of mandibles, chelicerae, or loosely, pedipalps. Their function is fundamentally for food acquisition, conveyance to the mouth, and… (More on Jaw)