living organisms see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Superkingdom Prokaryotae see Superkingdom Prokarya
     Kingdom Monera Haeckel 1866 see Domain Bacteria Woese et al. 1990
       Division Bacteria (Haeckel 1894) see Domain Bacteria Woese et al. 1990
         "Gram-negative anaerobic bacteria"
           Family Bacteroidaceae Pribram 1933 (Approved Lists 1980)
             Genus Bacteroides Castellani and Chalmers 1919 (Approved Lists 1980)
               1 Bacteroides fragilisᵀ (Veillon and Zuber 1898) Castellani and Chalmers 1919 (Approved Lists 1980)
               2 Bacteroides vulgatus Eggerth and Gagnon 1933 (Approved Lists 1980)