Arthropods
An arthropod is an invertebrate animal with an exoskeleton. It includes the insects, arachnids, crustaceans, and others. Arthropods are characterized by their jointed limbs and cuticles. Arthropods are covered with a tough or resistant Exoskeleton, which may be mineralised or constructed of a tough polymer such as chitin, and is often Biomineralized with materials such as calcium carbonate. This external skeleton is moulted as the organism grows.