prokaryotes - bacteria see Domain Bacteria Woese et al. 1990 stat. inval.
   Domain "Bacteria" Woese et al. 1990 stat. inval. see Domain Bacteria Woese et al. 2024
     Phylum "Aquificae" Reysenbach 2002 stat. inval. [monotypic] see Phylum Aquificota Reysenbach 2021
       Class Aquificae Reysenbach 2002 [monotypic]
         Order Aquificales Reysenbach 2002
           Family Hydrogenothermaceae Eder and Huber 2003
             1 Genus Hydrogenothermus Stöhr et al. 2001
             2 Genus Persephonella Götz et al. 2002
             3 Genus Sulfurihydrogenibium Takai et al. 2003
             4 Genus Venenivibrio Hetzer et al. 2008