[Phylum] [Arthropoda] Siebold, 1848 - arthropods
   Chelicerata Heymons, 1901
     Euchelicerata Weygoldt & Paulus, 1979
       [Subclass] Acari Leach, 1817 - mites and ticks
         [Order] Acariformes Zakhvatkin, 1952 see Superorder Acariformes Zakhvatkin, 1952
           Suborder Trombidiformes Reuter, 1909 see Order Trombidiformes Reuter, 1909
             Infraorder Prostigmata Kramer, 1877 see Suborder Prostigmata Kramer, 1877
               Supercohort Anystides van der Hammen, 1972 see Infraorder Anystina van der Hammen, 1972
                 Cohort Parasitengona Oudemans, 1909 - chiggers, velvet mites, water mites, and their relatives see Hyporder Parasitengona Oudemans, 1909
                   Subcohort Hydracarnidiae Dunlop, Penney & Jekel, 2010, orth. inval. see Subcohort Hydrachnidiae
                     Superfamily Hydryphantoidea Piersig, 1896 - water mites
                       1 Family Ctenothyadidae Lundblad, 1936
                       2 Family Eupatrellidae Viets, 1935 see Family Hydryphantidae Piersig, 1896
                       3 Family Hydrodromidae Viets, 1936
                       4 Family Hydryphantidae Piersig, 1896
                       5 Family Malgasacaridae Tuzovskij, Gerecke & Goldschmidt, 2007 see Family Zelandothyadidae Cook, 1983
                       6 Family Rhynchohydracaridae Lundblad, 1936
                       7 Family Teratothyadidae Viets, 1929
                       8 Family Thermacaridae Sokolow, 1927
                       9 Family Zelandothyadidae Cook, 1983