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 Order Clostridiales Prévot 1953 (Approved Lists 1980) Family "Heliobacteriaceae" nom. inval. see Family Heliobacteriaceae Madigan and Asao 2010 Genus Heliobacterium Gest and Favinger 1985