[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   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 "Peptostreptococcaceae" see Family Peptostreptococcaceae Ezaki 2010
             01 Genus Peptostreptococcus Kluyver and van Niel 1936 (Approved Lists 1980)
             02 Genus Anaerococcus Ezaki et al. 2001
             03 Genus Filifactor Collins et al. 1994
             04 Genus Finegoldia Murdoch and Shah 2000
             05 Genus Fusibacter Ravot et al. 1999
             06 Genus Gallicola Ezaki et al. 2001
             07 Genus Helcococcus Collins et al. 1993
             08 Genus Micromonas Murdoch and Shah 2000 nom. illeg. see Genus Parvimonas Tindall and Euzéby 2006
             09 Genus Peptoniphilus Ezaki et al. 2001
             10 Genus Sedimentibacter Breitenstein et al. 2002
             11 Genus Sporanaerobacter Hernandez-Eugenio et al. 2002
             12 Genus Tissierella Collins and Shah 1986