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 Rhizaria Cavalier-Smith, 2002
                                 Phylum Retaria Cavalier-Smith, 2002
                                   Subphylum Foraminifera d'Orbigny, 1826
                                     Globothalamea Pawlowski, Holzmann & Tyszka, 2013
                                       Class Rotaliata Mikhalevich, 1980 - hyaline foraminifers
                                         Subclass Rotalianaᵀ Mikhalevich, 1980
                                           Superorder Buliminoida Saidova, 1981
                                             Order Bolivinitida Saidova, 1981
                                               Suborder "Spirobolivina" Mikhalevich, 1998
                                                 Family Spirobolivinidaeᵀ Saidova, 1981
                                                   Subfamily Sigmavirgulininae Saidova, 1981 [monotypic]
                                                     Genus Sigmavirgulinaᵀ Loeblich & Tappan, 1957
                                                       Sigmavirgulina tortuosa (Brady, 1881)