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 "Methanomicrobia"
                   Order Methanomicrobialesᵀ Balch and Wolfe 1981
                     Family Methanomicrobiaceaeᵀ Balch and Wolfe 1981
                       Genus Methanoculleus Maestrojuán et al. 1990
                         01 Methanoculleus bourgensis corrig. (Ollivier et al. 1986) Maestrojuán et al. 1990
                         02 Methanoculleus chikugoensis Dianou et al. 2001
                         03 Methanoculleus horonobensis Shimizu et al. 2013
                         04 Methanoculleus hydrogenitrophicus Tian et al. 2010
                         05 Methanoculleus marisnigri (Romesser et al. 1981) Maestrojuán et al. 1990
                         06 Methanoculleus olentangyi (Corder et al. 1988) Maestrojuán et al. 1990
                         07 Methanoculleus palmolei Zellner et al. 1998
                         08 Methanoculleus receptaculi Cheng et al. 2008
                         09 Methanoculleus submarinus Mikucki et al. 2003
                         10 Methanoculleus taiwanensis Weng et al. 2015
                         11 Methanoculleus thermophilus corrig. (Rivard and Smith 1982) Maestrojuán et al. 1990