life see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Empire Eukaryota (Chatton, 1925) see Domain Eukaryota Chatton, 1925
     Superkingdom Metakaryota 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 Alveolata Cavalier-Smith, 1991 see Superphylum Alveolata Cavalier-Smith, 1991
                 Superphylum Heterokaryota Hickson, 1903 [monotypic]
                   Phylum Ciliophora Doflein, 1901 - ciliates
                     Class Oligohymenophorea de Puytorac et al., 1974 - oligohymenophoreans
                       1 Subclass Hymenostomatia (Delage & Hérouard, 1896) Cavalier-Smith, 1993 - hymenostome ciliates
                       2 Subclass Peritrichia Stein, 1859
                       3 Subclass Astomatia Schewiakoff, 1896
                       4 Subclass Apostomatia Chatton & Lwoff, 1928
                       5 Subclass Plagiopylia Small & Lynn, 1985