living organisms see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Superkingdom Eukaryotae see Domain Eukaryota Chatton, 1925
     Kingdom Animalia Linnaeus, 1758 - animals
       Subkingdom Protozoa Goldfuss, 1818 see Kingdom Protozoa Goldfuss, 1818
         Phylum Ciliophora Doflein, 1901 - ciliates
           Class Polyhymenophora Jankowski, 1967 see Class Spirotrichea Bütschli, 1889
             Subclass Spirotricha see Class Spirotrichea Bütschli, 1889
               Order Heterotrichida Stein, 1859 - heterotrichs
                 Suborder Heterotrichina see Order Heterotrichida Stein, 1859
                   01 Family Spirostomidae Stein, 1867
                   02 Family Phacodiniidae Corliss, 1979
                   03 Family Metopidae Kahl, 1927
                   04 Family Condylostomatidae Kahl, in Doflein & Reichenow, 1929
                   05 Family Reichenowellidae Kahl, 1932
                   06 Family Climacostomidae Repak, 1972
                   07 Family Stentoridae Carus, 1863
                   08 Family Bursariidae Bory de St. Vincent, 1826
                   09 Family Chattonidiidae Villeneuve-Brachon, 1940
                   10 Family Peritromidae Stein, 1867