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 Fibrobacteres-Chlorobi-Bacteroidetes (FCB) Gupta 2004
               Phylum Bacteroidetes Krieg et al. 2012
                 Class Cytophagia Nakagawa 2012 [monotypic]
                   Order Cytophagalesᵀ Leadbetter 1974 (Approved Lists 1980)
                     Family Cytophagaceaeᵀ Stanier 1940 (Approved Lists 1980)
                       Genus Spirosoma Migula 1894 (Approved Lists 1980)
                         1 Spirosoma lingualeᵀ Migula 1894 (Approved Lists 1980)
                         2 Spirosoma luteum Finster et al. 2009
                         3 Spirosoma panaciterrae Ten et al. 2009
                         4 Spirosoma rigui Baik et al. 2007
                         5 Spirosoma spitsbergense Finster et al. 2009