[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Domain "Archaea" Woese et al. 1990
     Phylum "Euryarchaeota" Garrity and Holt 2001
       Class "Methanomicrobia"
         Order Methanomicrobiales Balch and Wolfe 1981
           Genus Methanocalculus Ollivier et al. 1998
             1 Methanocalculus halotolerans Ollivier et al. 1998
             2 Methanocalculus chunghsingensis Lai et al. 2004
             3 Methanocalculus pumilus Mori et al. 2000
             4 Methanocalculus taiwanensis Lai et al. 2002