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]
           Domain Bacteria Woese et al. 1990 [paraphyletic?]
             Superphylum Terrabacteria Battistuzzi et al. 2004
               Phylum "Actinobacteria" Garrity and Holt 2001
                 Class Actinobacteriaᵀ Stackebrandt et al. 1997
                   Order Bifidobacteriales Stackebrandt et al. 1997 [monotypic]
                     Family Bifidobacteriaceae Stackebrandt et al. 1997
                       Genus Bifidobacteriumᵀ Orla-Jensen 1924 (Approved Lists 1980)
                         Bifidobacterium thermacidophilum Dong et al. 2000
                           1 Bifidobacterium thermacidophilum subsp. porcinum Zhu et al. 2003
                           2 Bifidobacterium thermacidophilum subsp. thermacidophilumᵀ (Dong et al. 2000) Zhu et al. 2003