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]
           Domain Bacteria Woese et al. 2024
             Kingdom Bacillatiᵀ (Gibbons and Murray 1978) Oren and Göker 2024
               Phylum Cyanobacteriota Oren et al. 2022
                 Class Chroococcophyceaeᵀ Hollerbach et al. 1953
                   Order Chroococcales corrig. Ardissone 1887
                     Family Microcystaceae Elenkin 1933, sedis mutabilis
                       Genus †Palaeomicrocystis Korde 1955