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 Natranaerobiales Mesbah et al. 2007 [monotypic]
                     Family Natranaerobiaceaeᵀ Mesbah et al. 2007
                       Genus Natranaerobiusᵀ Mesbah et al. 2007
                         1 Natranaerobius thermophilusᵀ Mesbah et al. 2007
                         2 Natranaerobius trueperi Mesbah and Wiegel 2009