Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
           Domain Bacteria Woese et al. 2024
             Kingdom Bacillatiᵀ (Gibbons and Murray 1978) Oren and Göker 2024
               Phylum Bacillotaᵀ Gibbons and Murray 2021
                 Class Clostridia Rainey 2010
                   Order Caldicellulosiruptorales Chuvochina et al. 2024 [monotypic]
                     Family Caldicellulosiruptoraceaeᵀ Chuvochina et al. 2024 [monotypic]
                       Genus Caldicellulosiruptorᵀ Rainey et al. 1995
                         1 Caldicellulosiruptor acetigenus (Nielsen et al. 1994) Onyenwoke et al. 2006
                         2 Caldicellulosiruptor bescii Yang et al. 2010
                         3 Caldicellulosiruptor hydrothermalis Miroshnichenko et al. 2008
                         4 Caldicellulosiruptor kristjanssonii Bredholt et al. 1999
                         5 Caldicellulosiruptor kronotskyensis Miroshnichenko et al. 2008
                         6 Caldicellulosiruptor lactoaceticus Mladenovska et al. 1997
                         7 "Caldicellulosiruptor obsidiansis" Hamilton-Brehm et al. 2010
                         8 Caldicellulosiruptor owensensis Huang et al. 1998
                         9 Caldicellulosiruptor saccharolyticusᵀ Rainey et al. 1995