prokaryotes - bacteria see Domain Bacteria Woese et al. 1990 stat. inval.
   Domain "Archaea" Woese et al. 1990 stat. inval. see Domain Archaea Woese et al. 2024
     Phylum "Euryarchaeota" Garrity and Holt 2002 stat. inval. see Kingdom Methanobacteriati (Garrity and Holt 2023) Oren and Göker 2024
       Class Thermoplasmata Reysenbach 2002 [monotypic]
         Order Thermoplasmatales Reysenbach 2002
           1 Family Cuniculiplasmataceae Golyshina et al. 2016 [monotypic]
           2 Family Ferroplasmaceae (sic) Golyshina et al. 2000 see Family Ferroplasmataceae corrig. Golyshina et al. 2000
           3 Family Picrophilaceae Schleper et al. 1996 [monotypic]
           4 Family Thermoplasmataceae Reysenbach 2002 [monotypic]
           5 Genus Thermogymnomonas Itoh et al. 2007, incertae sedis