[living organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Superkingdom Prokaryota Margulis 1974 nom. nud.
     Kingdom Bacteria Cavalier-Smith 2002 stat. inval. - bacteria see Domain Bacteria Woese et al. 1990 stat. inval.
       Subkingdom Negibacteria Cavalier-Smith 2002 stat. inval. - negibacteria see Domain Bacteria Woese et al. 1990 stat. inval.
         Phylum Aquificae Reysenbach 2002 stat. inval. [monotypic] see Phylum Aquificota Reysenbach 2021
           1 Class Aquificae Reysenbach 2002 [monotypic]