[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 Clostridiaceae Pribram 1933 (Approved Lists 1980)
             01 Genus Clostridium Prazmowski 1880 (Approved Lists 1980)
             02 Genus Acetanaerobacterium Chen and Dong 2004
             03 Genus Acetivibrio Patel et al. 1980
             04 Genus Acidaminobacter Stams and Hansen 1985
             05 Genus Alkaliphilus Takai et al. 2001
             06 Genus Anaerobacter Duda et al. 1996
             07 Genus Anaerotruncus Lawson et al. 2004
             08 Genus Anoxynatronum Garnova et al. 2003
             09 Genus Bryantella Wolin et al. 2004 see Genus Marvinbryantia Wolin et al. 2008
             10 Genus Caminicella Alain et al. 2002
             11 Genus Caloramator Collins et al. 1994
             12 Genus Caloranaerobacter Wery et al. 2001
             13 Genus Coprobacillus Kageyama and Benno 2000
             14 Genus Dorea Taras et al. 2002
             15 Genus Ethanoligenens Xing et al. 2006
             16 Genus Faecalibacterium Duncan et al. 2002
             17 Genus Fastidiosipila Falsen et al. 2005
             18 Genus Garciella Miranda-Tello et al. 2003
             19 Genus Gracilibacter Lee et al. 2006
             20 Genus Guggenheimella Wyss et al. 2005
             21 Genus Hespellia Whitehead et al. 2004
             22 Genus Natronincola corrig. Zhilina et al. 1999
             23 Genus Oxobacter Collins et al. 1994
             24 Genus Parasporobacterium Lomans et al. 2004
             25 Genus Sarcina Goodsir 1842 (Approved Lists 1980)
             26 Genus Soehngenia Parshina et al. 2003
             27 Genus Sporacetigenium Chen et al. 2006
             28 Genus Sporobacter Grech-Mora et al. 1996
             29 Genus Subdoligranulum Holmstrøm et al. 2004
             30 Genus Tepidibacter Slobodkin et al. 2003
             31 Genus Tepidimicrobium Slobodkin et al. 2006
             32 Genus Thermobrachium Engle et al. 1996
             33 Genus Thermohalobacter Cayol et al. 2000
             34 Genus Tindallia Kevbrin et al. 1999