What are the 5 major groups of invertebrates?

Under the arthropoda phylum are subphyla Chelicerata, Myriapoda, Crustacea, and Hexapoda. There is also an the extinct Trilobite subphylum (and an extinct class Marrellomorpha). The chelicerata include Spiders, scorpions, mites, etc. Myriapods include centipedes and millipedes. Crustaceans include lobsters, krill, crabs, shrimp, woodlice, etc. Hexapoda include the class Insecta, the insects.