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?]
             Phylum Thermotogae Reysenbach 2001 [monotypic]
               Class Thermotogaeᵀ Reysenbach 2002 [monotypic]
                 Order Thermotogalesᵀ Reysenbach 2002 [monotypic]
                   Family Thermotogaceaeᵀ Reysenbach 2002
                     Genus Fervidobacterium Patel et al. 1985
                       1 Fervidobacterium changbaicum Cai et al. 2007
                       2 Fervidobacterium gondwanense Andrews and Patel 1996
                       3 Fervidobacterium islandicum Huber et al. 1991
                       4 Fervidobacterium nodosumᵀ Patel et al. 1985
                       5 Fervidobacterium pennivorans corrig. Friedrich and Antranikian 1999
                       6 Fervidobacterium riparium Podosokorskaya et al. 2011