Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
           Domain Bacteria Woese et al. 2024
             Kingdom Pseudomonadati (Gibbons and Murray 1978) Oren and Göker 2024
               Phylum Aquificota Reysenbach 2021 [monotypic]
                 Class Aquificiaᵀ corrig. Reysenbach 2002
                   Order Aquificalesᵀ Reysenbach 2002
                     Family Hydrogenothermaceae Eder and Huber 2003
                       1 Genus Hydrogenothermusᵀ Stöhr et al. 2001 [monotypic]
                       2 Genus Persephonella Götz et al. 2002
                       3 Genus Sulfurihydrogenibium Takai et al. 2003
                       4 Genus Venenivibrio Hetzer et al. 2008 [monotypic]