Procaryotic Genera
   Domain "Bacteria" Woese et al. 1990
     Phylum Proteobacteria Garrity and Holt 2001 see Phylum Proteobacteria Garrity et al. 2005
       Class "Deltaproteobacteria" Garrity et al. 2001 nom. ined. see Class Deltaproteobacteria Kuever et al. 2006
         Order "Desulfovibrionales" Garrity et al. 2001 nom. ined. see Order Desulfovibrionales Kuever et al. 2006
           Family "Desulfovibrionaceae" Devereux et al. 1990 see Family Desulfovibrionaceae Kuever et al. 2006
             Genus Lawsonia McOrist et al. 1995