organisms see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Domain eukaryotes see Domain Eukaryota Chatton, 1925
     alveolates Cavalier-Smith see [unranked] Alveolata Cavalier-Smith, 1991
       Phylum Ciliophora Doflein, 1901 - ciliates
         Subphylum Intramacronucleata Lynn, 1996 - amphiesmates
           Class Litostomatea Small & Lynn, 1981
             Subclass Haptoria Corliss, 1974
               Order Haptoridaᵀ Corliss, 1974
                 01 Family Pseudoholophryidae Berger et al., 1984
                 02 Family Didiniidae Poche, 1913
                 03 Family Pseudotrachelocercidae Song, 1990
                 04 Family Actinobolinidae Kahl, 1930
                 05 Family Tracheliidae Ehrenberg, 1838
                 06 Family Helicoprorodontidae Small & Lynn, 1985
                 07 Family Pleuroplitidae Foissner, 1996
                 08 Family Lacrymariidae de Fromentel, 1876
                 09 Family Homalozoonidae Jankowski, 1980
                 10 Family Enchelyidae Ehrenberg, 1838
                 11 Family Acropisthiidae Foissner & Foissner, 1988
                 12 Family Spathidiidae Kahl, 1929
                 13 Family Trachelophyllidae Kent, 1882