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
                     1.1 "novel archaeal group 1 (NAG1)"
                     1.2 Order Thermoprotealesᵀ Zillig and Stetter 1982
                     2.1 Order Acidilobales Prokofeva et al. 2009
                     2.2 Order Desulfurococcales Huber and Stetter 2002
                     2.3 Order Fervidicoccales Perevalova et al. 2010 [monotypic]
                     3 Order Sulfolobales Stetter 1989 [monotypic]
                     4 Order Cenarchaeales Cavalier-Smith 2002 [monotypic]