What is an arthropod?
Arthropods are “invertebrate” (have no internal backbone) animals that have an external skeletal support system (sometimes called a cuticle, carapace, or shell) and jointed appendages. Arthropods are the largest major group (phylum) of animals on Earth. The phylum Arthropoda includes the insects, crustaceans, chelicerates (spiders, scorpions, ticks, mites, horseshoe crabs, harvestmen, and others), centipedes, millipedes, and others.
