[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 Hygrobatoidea Koch, 1842
                       01 Family Astacocrotonidae Thor, 1927
                       02 Family Aturidae Thor, 1900
                       03 Family Feltriidae Viets, 1926
                       04 Family Ferradasiidae Cook, 1980
                       05 Family Frontipodopsidae Viets, 1931
                       06 Family Hygrobatidae Koch, 1842
                       07 Family Lethaxonidae Cook, Smith & Harvey, 2000
                       08 Family Limnesiidae Thor, 1900
                       09 Family Omartacaridae Cook, 1963
                       10 Family Pionidae Thor, 1900
                       11 Family Pontarachnidae Koenike, 1910
                       12 Family Unionicolidae Oudemans, 1909
                       13 Family Wettinidae Cook, 1956