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 Desulfurococcales Huber and Stetter 2002
                       Family Pyrodictiaceae Burggraf et al. 1997
                         1 Genus Pyrodictiumᵀ Stetter et al. 1984
                         2 Genus Hyperthermus Zillig et al. 1991 [monotypic]
                         3 Genus Pyrolobus Blöchl et al. 1999 [monotypic]