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]
               Phylum Euryarchaeota Garrity and Holt 2001
                 Class Methanobacteria Boone 2002 [monotypic]
                   Order Methanobacterialesᵀ Balch and Wolfe 1981
                     Family Methanobacteriaceaeᵀ Barker 1956 (Approved Lists 1980)
                       Genus Methanothermobacter Wasserfallen et al. 2000
                         1 Methanothermobacter crinale Cheng et al. 2012
                         2 Methanothermobacter defluvii (Kotelnikova et al. 1994) Boone 2002
                         3 Methanothermobacter marburgensis Wasserfallen et al. 2000
                         4 Methanothermobacter tenebrarum Nakamura et al. 2013
                         5 Methanothermobacter thermautotrophicusᵀ (Zeikus and Wolfe 1972) Wasserfallen et al. 2000
                         6 Methanothermobacter thermoflexus (Kotelnikova et al. 1994) Boone 2002
                         7 Methanothermobacter thermophilus (Laurinavichus et al. 1990) Boone 2002
                         8 Methanothermobacter wolfeii corrig. (Winter et al. 1985) Wasserfallen et al. 2000