Procaryotic Genera
   Domain "Bacteria" Woese et al. 1990
     Phylum Aquificae Reysenbach 2001 [monotypic]
       Class Aquificae Reysenbach 2001 nom. inval. [monotypic] see Class Aquificae Reysenbach 2002
         Order Aquificalesᵀ Reysenbach 2001 nom. inval. see Order Aquificales Reysenbach 2002
           Family Aquificaceae Reysenbach 2001 nom. inval. see Family Aquificaceae Reysenbach 2002
             Genus Calderobacterium Kryukov et al. 1984 see Genus Hydrogenobacter Kawasumi et al. 1984