Procaryotic Genera
   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
         1 Order Clostridiales Prévot 1953 (Approved Lists 1980)
         2 Order "Thermoanaerobacteriales" [monotypic] see Order Thermoanaerobacterales Wiegel, 2010
         3 Order Haloanaerobiales Rainey and Zhilina 1995 see Order Halanaerobiales corrig. Rainey and Zhilina 1995