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 Thermotogati Battistuzzi and Hedges 2024
               Phylum Thermotogotaᵀ Reysenbach 2021 [monotypic]
                 Class Thermotogaeᵀ Reysenbach 2002
                   Order Thermotogalesᵀ Reysenbach 2002
                     Family Fervidobacteriaceae Bhandari and Gupta 2014
                       Genus Fervidobacteriumᵀ Patel et al. 1985
                         1 Fervidobacterium changbaicum Cai et al. 2007
                         2 Fervidobacterium gondwanense Andrews and Patel 1996
                         3 Fervidobacterium islandicum Huber et al. 1991
                         4 Fervidobacterium nodosumᵀ Patel et al. 1985
                         5 Fervidobacterium pennivorans corrig. Friedrich and Antranikian 1999
                         6 Fervidobacterium riparium Podosokorskaya et al. 2011