procaryotes
   Domain Bacteria Woese et al. 1990 stat. inval. see Domain Bacteria Woese et al. 2024
     Phylum Proteobacteria Garrity and Holt 2001 nom. nud. see Phylum Proteobacteria Garrity et al. 2005 stat. inval.
       Class "Deltaproteobacteria" "Garrity and Holt 2001" nom. nud. see Class Deltaproteobacteria Kuever et al. 2006
         Order "Syntrophobacterales" "Garrity and Holt 2001" nom. nud. see Order Syntrophobacterales Kuever et al. 2006
           Family "Syntrophaceae" "Garrity and Holt 2001" nom. nud. see Family Syntrophaceae Kuever et al. 2006
             1 Genus Syntrophus Mountfort et al. 1984
             2 Genus Smithella Liu et al. 1999