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 Thermoanaerobacterales Wiegel 2010
                     Family Thermoanaerobacteraceaeᵀ Wiegel 2010
                       01 Genus Aceticella Frolov et al. 2024
                       02 Genus Ammonifex Huber and Stetter 1996
                       03 Genus Brockia Perevalova et al. 2013 [monotypic]
                       04 Genus Caldanaerobacter Fardeau et al. 2004
                       05 Genus Caldanaerobius Lee et al. 2008
                       06 Genus Calderihabitans Yoneda et al. 2013
                       07 Genus Caloribacterium Slobodkina et al. 2012 [monotypic]
                       08 Genus Carboxydibrachium corrig. Sokolova et al. 2001 [monotypic]
                       09 Genus Carboxydothermus Svetlichny et al. 1991
                       10 Genus Desulfothermobacter Frolov et al. 2018
                       11 Genus Desulfovirgula Kaksonen et al. 2007 [monotypic]
                       12 Genus Gelria Plugge et al. 2002 [monotypic]
                       13 Genus Thermoanaerobacterᵀ Wiegel and Ljungdahl 1982
                       14 Genus Thermoanaerobacterium Lee et al. 1993
                       15 Genus Thermodesulfitimonas Slobodkina et al. 2017