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 Firmicutes corrig. Gibbons and Murray 1978 (Approved Lists 1980)
                 Class Clostridia Rainey 2010
                   Order Clostridialesᵀ Prévot 1953 (Approved Lists 1980)
                     Family Syntrophomonadaceae Zhao et al. 1993
                       1 Genus Syntrophomonasᵀ McInerney et al. 1982
                       2 Genus Dethiobacter Sorokin et al. 2008 [monotypic]
                       3 Genus Fervidicola Ogg and Patel 2009 [monotypic]
                       4 Genus Pelospora Matthies et al. 2000 [monotypic]
                       5 Genus Syntrophothermus Sekiguchi et al. 2000 [monotypic]
                       6 Genus Thermohydrogenium Zacharova et al. 1996 [monotypic]
                       7 Genus Thermosyntropha Svetlitshnyi et al. 1996 [monotypic]