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 Syntrophomonadaceae Zhao et al. 1993
             Genus Fervidicola Ogg and Patel 2009