Phylum Arthropoda Siebold, 1848 - arthropods
   Subphylum Crustacea Brünnich, 1772 - crustaceans see Superclass Crustacea Pennant, 1777
     Class Maxillopoda Dahl, 1956 see Subphylum Pancrustacea Zrzavý et al., 1997
       1 Subclass Thecostraca Gruvel, 1905 - barnacles
       2 Subclass Tantulocarida Boxshall & Lincoln, 1983 - tantulocarids
       3 Subclass Branchiura Thorell, 1864 - fish lice
       4 Subclass Pentastomida Diesing, 1836 - tongue worms
       5 Subclass Mystacocarida Pennak & Zinn, 1943 - mystacocarids
       6 Subclass Copepoda H. Milne-Edwards, 1840 - copepods