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
           1 Family Aquificaceae Reysenbach 2002
           2 Family Desulfurobacteriaceae L'Haridon et al. 2006
           3 Family Hydrogenothermaceae Eder and Huber 2003
           4 Genus Thermosulfidibacter Nunoura et al. 2008, incertae sedis