Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
           Clade neomura Cavalier-Smith, 1987
             Domain Eukaryota Chatton, 1925 - eukaryotes
               Clade discaria Cavalier-Smith, 2021
                 Clade natates Cavalier-Smith, 2021
                   Clade photaria Cavalier-Smith, 2021
                     Clade eucorta Cavalier-Smith, 2021
                       Superkingdom Corticata Lankester, 1878 - corticates
                         Kingdom Chromista Caval.-Sm. (1981) - chromists
                           Subkingdom Harosa Cavalier-Smith, 2010
                             Clade Sar Adl et al. 2012 [Simpson & Dunthorn 2020]
                               Infrakingdom Halvaria Cavalier-Smith, 2010
                                 Superphylum Alveolata Cavalier-Smith, 1991
                                   Phylum Ciliophora Doflein, 1901 - ciliates
                                     Subphylum Intramacronucleata Lynn, 1996 - amphiesmates
                                       Class Spirotrichea Bütschli, 1889
                                         Subclass Oligotrichia Bütschli, 1889 [monotypic]
                                           Order Strombidiida Petz & Foissner, 1992
                                             Family Tontoniidae Agatha, 2004
                                               1 Genus Tontoniaᵀ Fauré-Fremiet, 1961
                                               2 Genus Paratontonia Jankowski, in Borkin, ed., 1978
                                               3 Genus Spirotontonia Agatha, 2004
                                               4 Genus Pseudotontonia Agatha, 2004