[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Domain Bacteria Woese et al. 1990 stat. inval. see Domain Bacteria Woese et al. 2024
     Phylum Firmicutes (Gibbons and Murray 1978) Garrity and Holt 2001 stat. inval. see Phylum Bacillota Gibbons and Murray 2021
       Class "Clostridia" "Garrity and Holt 2001" nom. nud. see Class Clostridia Rainey 2010
         Order "Thermoanaerobacteriales" "Garrity and Holt 2001" nom. nud. see Order Thermoanaerobacterales Wiegel 2009 nom. inval.
           Family "Thermoanaerobacteriaceae" "Garrity and Holt 2001" nom. nud. see Family Thermoanaerobacteraceae Wiegel 2009 nom. inval.
             Genus Thermoanaerobacterium Lee et al. 1993
               1 Thermoanaerobacterium thermosulfurigenes (Schink and Zeikus 1983) Lee et al. 1993
               2 Thermoanaerobacterium aotearoense Liu et al. 1996
               3 Thermoanaerobacterium polysaccharolyticum Cann et al. 2001 see Caldanaerobius polysaccharolyticus (Cann et al. 2001) Lee et al. 2008
               4 Thermoanaerobacterium saccharolyticum Lee et al. 1993
               5 Thermoanaerobacterium thermosaccharolyticum (McClung 1935) Collins et al. 1994
               6 Thermoanaerobacterium xylanolyticum Lee et al. 1993
               7 Thermoanaerobacterium zeae Cann et al. 2001 see Caldanaerobius zeae (Cann et al. 2001) Lee et al. 2008