Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         [crown] Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
           Clade neomura Cavalier-Smith, 1987
             Domain Archaea Woese et al. 1990 [paraphyletic]
               Superphylum TACK Guy and Ettema 2011
                 Phylum Crenarchaeota Garrity and Holt 2001
                   Class Thermoprotei Reysenbach 2002
                     Order Sulfolobales Stetter 1989 [monotypic]
                       Family Sulfolobaceaeᵀ Stetter 1989
                         1 Genus Sulfolobusᵀ Brock et al. 1972 (Approved Lists 1980)
                         2 Genus Acidianus Segerer et al. 1986
                         3 Genus Metallosphaera Huber et al. 1989
                         4 Genus Stygiolobus Segerer et al. 1991 [monotypic]
                         5 Genus Sulfurisphaera Kurosawa et al. 1998 [monotypic]
                         6 Genus Sulfurococcus Golovacheva et al. 1995