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 Negativicutes Marchandin et al. 2010
         1 Order Acidaminococcales Campbell et al. 2015 [monotypic]
         2 Order Selenomonadales Marchandin et al. 2010
         3 Order Veillonellales Campbell et al. 2015 [monotypic]