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 "Crenarchaeota" Garrity and Holt 2002 stat. inval. [monotypic] see Phylum Thermoproteota Garrity and Holt 2021
       Class Thermoprotei Reysenbach 2002
         1 Order Acidilobales Prokofeva et al. 2009
         2 Order Cenarchaeales Cavalier-Smith 2002 nom. inval., nom. rej. [monotypic] see Order Nitrosopumilales Qin et al. 2017
         3 Order Desulfurococcales Huber and Stetter 2002
         4 Order Fervidicoccales Perevalova et al. 2010 [monotypic]
         5 Order Sulfolobales Stetter 1989 [monotypic]
         6 Order Thermoproteales Zillig and Stetter 1982