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 Halanaerobiales corrig. Rainey and Zhilina 1995
           Family Halobacteroidaceae Zhilina and Rainey 1995
             Genus Halonatronum Zhilina et al. 2001