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
               "protists" incertae sedis
                 Group †Calcitarcha G.J.M. Versteegh, T. Servais, Streng, Munnecke & Vachard (2009), incertae sedis [polyphyletic] - calcispheres
                   01 Genus †Moravosphaera Langer (1997)
                   02 Genus †Radiina Reitlinger (1957)
                   03 Genus †Radiosphaera Reitlinger (1957)
                   04 Genus †Sinothoracosphaera K. Hou, X. Tian, Yancheng Chen, Z. Xuan, Xiuqing Liu & Bo (1991)
                   05 Genus †Calcisphaera Williamson (1880)
                   06 Genus †Pachysphaerina Conil & Lys (1968)
                   07 Genus †Polyderma Derville (1950)
                   08 Genus †Quasipolyderma Conil & Lys (1964)
                   09 Genus †Gildaella Trejo (1983)
                   10 Genus †Schizosphaerella Deflandre & P.J.L. Dang. (1938)
                   11 Genus †Asterosphaerella Villain (1975)
                   12 Genus †Barnesiella Trejo (1983)
                   13 Genus †Cimicellus Odin (2008)
                   14 Genus †Globulella Odin (2008)
                   15 Genus †Lucernellus Odin (2008)
                   16 Genus †Nannoconoides Trejo (1983)
                   17 Genus †Pilella Odin (2008)
                   18 Genus †Piperella Odin (2008)
                   19 Genus †Pseudopithonella Trejo (1983)
                   20 Genus †Stomiosporella Trejo (1983)
                   21 Genus †Tubella Odin (2008)
                   22 Genus †Vasculum Odin (2008)
                   23 †"Pithonelloid taxa"
                   24 †"Gilianelloid taxa"
                   25 Genus †Chonesphaera Klumpp (1953)
                   26 Genus †Bolboforma von Daniels & Spiegler (1974)
                   27 Genus †Bachmayerella Rögl & H. Franz (1979)