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 Pseudomonadati (Gibbons and Murray 1978) Oren and Göker 2024
               Phylum Fibrobacterota Garrity and Holt 2021
                 Class Fibrobacteriaᵀ Spain et al. 2012
                   Order Fibrobacteralesᵀ Spain et al. 2012 [monotypic]
                     Family Fibrobacteraceaeᵀ Spain et al. 2012
                       Genus Fibrobacterᵀ Montgomery et al. 1988
                         Fibrobacter succinogenes (Hungate 1950) Montgomery et al. 1988
                           Fibrobacter succinogenes subsp. elongatus corrig. Montgomery et al. 1988