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]
           Domain Bacteria Woese et al. 1990 [paraphyletic?]
             Superphylum Terrabacteria Battistuzzi et al. 2004
               Phylum Cyanobacteria (ex Stanier 1974) Cavalier-Smith 2002 - cyanobacteria
                 Class "Cyanobacteria" Cavalier-Smith, 2002
                   Subclass Oscillatoriophycideae
                     Order Chroococcales Wettst. (1924)
                       Family Hydrococcaceae Kützing (1843)
                         1 Genus Onkonema L. Geitler (1933)
                         2 Subfamily Hydrococcoideaeᵀ
                         3 Genus Myxohyella L. Geitler (1925)
                         4.1 Subfamily Hyelloideae
                         4.2 Subfamily Pascherinematoideae
                         4.3 Subfamily Podocapsoideae
                         4.4 Subfamily Solentioideae
                         5 Genus Chroococcidium L. Geitler (1933)
                         6 Genus Ercegovicia G. De Toni (1936)