prokaryotes - bacteria see Domain Bacteria Woese et al. 1990
   Domain "Bacteria" Woese et al. 1990
     Phylum "Firmicutes" corrig. Gibbons and Murray 1978 (Approved Lists 1980)
       Class Clostridia Rainey 2010
         Order Clostridiales Prévot 1953 (Approved Lists 1980)
           Family Clostridiaceae Pribram 1933 (Approved Lists 1980)
             01 Genus Alkaliphilus Takai et al. 2001
             02 Genus Anaerobacter Duda et al. 1996
             03 Genus Anaerosalibacter Rezgui et al. 2012
             04 Genus Anaerosporobacter Jeong et al. 2007
             05 Genus Anoxynatronum Garnova et al. 2003
             06 Genus Asaccharospora Gerritsen et al. 2014
             07 Genus Brassicibacter Fang et al. 2012
             08 Genus Butyricicoccus Eeckhaut et al. 2008
             09 Genus Caldisalinibacter Ben Hania et al. 2015
             10 Genus Caloramator Collins et al. 1994
             11 Genus Caloranaerobacter Wery et al. 2001
             12 Genus Caminicella Alain et al. 2002
             13 Genus Cellulosibacter Watthanalamloet et al. 2012
             14 Genus Clostridiisalibacter Liebgott et al. 2008
             15 Genus Clostridium Prazmowski 1880 (Approved Lists 1980)
             16 Genus Crassaminicella Lakhal et al. 2015
             17 Genus Fervidicella Ogg and Patel 2010
             18 Genus Fonticella Fraj et al. 2013
             19 Genus Geosporobacter Klouche et al. 2007
             20 Genus Hungatella Kaur et al. 2014
             21 Genus Hydrogenispora Liu et al. 2014
             22 Genus Keratinibaculum Huang et al. 2015
             23 Genus Lactonifactor Clavel et al. 2007
             24 Genus Lutispora Shiratori et al. 2008
             25 Genus Natronincola corrig. Zhilina et al. 1999
             26 Genus Oceanirhabdus Pi et al. 2013
             27 Genus Oxobacter Collins et al. 1994
             28 Genus Proteiniclasticum Zhang et al. 2010
             29 Genus Saccharofermentans Chen et al. 2010
             30 Genus Salimesophilobacter Zhang et al. 2013
             31 Genus Sarcina Goodsir 1842 (Approved Lists 1980)
             32 Genus Sporosalibacterium Rezgui et al. 2011
             33 Genus Tepidimicrobium Slobodkin et al. 2006
             34 Genus Thermobrachium Engle et al. 1996
             35 Genus Thermohalobacter Cayol et al. 2000
             36 Genus Thermotalea Ogg and Patel 2009
             37 Genus Tindallia Kevbrin et al. 1999