Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         [crown] 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
                             [crown] Clade Sar Adl et al. 2012 [Simpson & Dunthorn 2020]
                               Infrakingdom Halvaria Cavalier-Smith, 2010
                                 Superphylum Heterokonta Caval.-Sm. (1986)
                                   Phylum Ochrophyta Caval.-Sm. (1995)
                                     Subphylum Khakista Caval.-Sm. (2000)
                                       Diatomea Kütz. (1844)
                                         Class Mediophyceae Medlin & Kaczmarska (2004) [paraphyletic] - bipolar centrics
                                           Order Thalassiosirales Glezer & I.V. Makarova (1986)
                                             Family Stephanodiscaceae Glezer & Makarova (1986)
                                               Genus Cyclostephanos Round (1987)
                                                 Cyclostephanos costatilimbus (H. Kobay. & H. Kobay.) Stoermer (1987)
                                                 Cyclostephanos delicatus (Genkel) Casper & Scheffler (1990)
                                                 Cyclostephanos dubius (Fricke) Round (1982)
                                                 Cyclostephanos invisitatus (Hohn & Hellermann) Theriot, Stoermer & Håkansson (1987)
                                                 Cyclostephanos malawiensis S.J. Casper & R. Klee
                                                 Cyclostephanos novaezeelandiae (Cleve) Round (1982)
                                                 Cyclostephanos tholiformis Stoermer, Håkansson & Theriot (1987)