Natura - nature
Ref: C. Linnaeus, 1748: 210
   actualia - actual entities
  Ref: A. Voltolini, 2006: 44 (note 19) [assumed position]
     Mundus Plinius - physical world
    Ref: C. Linnaeus, 1758: 5 [indirect position]; 24 Apr 2014.
       naturalia - natural bodies
      Ref: C. Linnaeus, 1758: 6 [implicit position]
         [crown] Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
        Ref: J. Wiemann et al., 2020: [13] [validation] [inferred position]
           Clade neomura Cavalier-Smith, 1987
          Ref: T. Cavalier-Smith, 2002b: 297 [inferred position]
             Domain Archaea Woese et al. 1990 [paraphyletic]
            Ref: J.P. Euzéby, 2016: [30 Aug 2017] [indirect position]; 19 Sep 2015.
               [Superphylum] TACK Guy and Ettema 2011
              Ref: D.H. Parks et al., 2017: fig. 3 [inferred rank]
                 Phylum Crenarchaeota Garrity and Holt 2001
                Ref: D.H. Parks et al., 2017: fig. 3
                   Class Thermoprotei Reysenbach 2002
                  Ref: J.P. Euzéby, 2016: [31 Aug 2017]
                     Order Thermoprotealesᵀ Zillig and Stetter 1982
                    Ref: G.M. Garrity et al., 2007: 6
                       Family Thermoproteaceaeᵀ Zillig and Stetter 1982
                      Ref: J.P. Euzéby, 2016: [1 Sep 2017]
                         Genus Pyrobaculum Huber et al. 1988
                        Ref: G.M. Garrity et al., 2007: 6
                           Pyrobaculum organotrophum Huber et al. 1988
                          Ref: G.M. Garrity et al., 2007: 6