Domain Bacteria Woese et al. 1990
   Phylum Firmicutes corrig. Gibbons and Murray 1978 (Approved Lists 1980)
     Class "Clostridia" Garrity et al. 2001 nom. ined. see Class Clostridia Rainey 2010
       Order Clostridiales Prévot 1953 (Approved Lists 1980)
         Family Peptococcaceae Rogosa 1971 (Approved Lists 1980)
           Genus Anaeroarcus Strömpl et al. 1999
           Genus Anaerosinus Strömpl et al. 1999
           Genus Anaerovibrio Hungate 1966 (Approved Lists 1980)
           Genus Carboxydothermus Svetlichny et al. 1991
           Genus Centipeda Lai et al. 1983
           Genus Dehalobacter Holliger et al. 1998
           Genus Dendrosporobacter Strömpl et al. 2000
           Genus Desulfitobacterium Utkin et al. 1994
           Genus Desulfonispora Denger et al. 1999
           Genus Desulfosporosinus Stackebrandt et al. 1997
           Genus Desulfotomaculum Campbell and Postgate 1965 (Approved Lists 1980)
           Genus Mitsuokella Shah and Collins 1983
           Genus Propionispira Schink et al. 1983
           Genus Succinispira Janssen and O'Farrell 1999
           Genus Syntrophobotulus Friedrich et al. 1996
           Genus Thermoterrabacterium Slobodkin et al. 1997 see Genus Carboxydothermus Svetlichny et al. 1991
           1 Genus Peptococcus Kluyver and van Niel 1936 (Approved Lists 1980)