prokaryotes - bacteria see Domain Bacteria Woese et al. 1990
   Domain "Archaea" Woese et al. 1990
     Phylum "Crenarchaeota" Garrity and Holt 2001 [monotypic]
       Class Thermoprotei Reysenbach 2002
         Order Desulfurococcales Huber and Stetter 2002
           Family Desulfurococcaceae Zillig and Stetter 1983
             1 Genus Aeropyrum Sako et al. 1996
             2 Genus Desulfurococcus Zillig and Stetter 1983
             3 Genus Ignicoccus Huber et al. 2000
             4 Genus Ignisphaera Niederberger et al. 2006
             5 Genus Staphylothermus Stetter and Fiala 1986
             6 Genus Stetteria Jochimsen et al. 1998
             7 Genus Sulfophobococcus Hensel et al. 1997
             8 Genus Thermodiscus Stetter 2003
             9 Genus Thermosphaera Huber et al. 1998