[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 "Acidaminococcaceae" Marchandin et al., 2010 see Family Acidaminococcaceae Marchandin et al. 2010
             Genus Megasphaera Rogosa 1971 (Approved Lists 1980)
               Megasphaera cerevisiae Engelmann and Weiss 1986