eukaryotes see Domain Eukaryota Chatton, 1925
   Kingdom Protozoa Goldfuss, 1818 - protozoa
     Subkingdom Dictyozoa Cavalier-Smith, 1991
       Branch Bikonta Cavalier-Smith, 1993
         Infrakingdom Neozoa Cavalier-Smith, 1993
           Parvkingdom Ciliomyxa Cavalier-Smith, 1993
             Phylum Opalozoa Cavalier-Smith, 1992 see Subphylum Opalozoa Cavalier-Smith, 1992
               Subphylum Opalinata Wenyon, 1926 see Superclass Opalinata Wenyon, 1926
                 Class Opalinea Wenyon, 1926
                   Order Opalinida Poche, 1913