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]
           Clade neomura Cavalier-Smith, 1987
             Domain Archaea Woese et al. 2024 [paraphyletic]
               Kingdom Methanobacteriati (Garrity and Holt 2023) Oren and Göker 2024
                 Phylum Methanobacteriotaᵀ Garrity and Holt 2023
                   Class Methanococci Boone 2002 [monotypic]
                     Order Methanococcalesᵀ Balch and Wolfe 1981
                       Family Methanococcaceaeᵀ Balch and Wolfe 1981
                         Genus Methanococcusᵀ Kluyver and van Niel 1936 (Approved Lists 1980)
                           Methanococcus vannielii Stadtman and Barker 1951 (Approved Lists 1980)