procaryotes
   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 Clostridiales Prévot 1953 (Approved Lists 1980) see Order Eubacteriales Buchanan 1917 (Approved Lists 1980)
           1 Family Clostridiaceae Pribram 1933 (Approved Lists 1980)
           2 Family "Lachnospiraceae" "Garrity and Holt 2001" nom. nud. see Family Lachnospiraceae Rainey 2010
           3 Family "Peptostreptococcaceae" "Garrity and Holt 2001" nom. nud. see Family Peptostreptococcaceae Ezaki 2010
           4 Family "Eubacteriaceae" "Garrity and Holt 2001" nom. nud. see Family Eubacteriaceae Ludwig et al. 2010
           5 Family Peptococcaceae Rogosa 1971 (Approved Lists 1980)
           6 Family "Heliobacteriaceae" "Garrity and Holt 2001" nom. nud. see Family Heliobacteriaceae Madigan and Asao 2010
           7 Family "Acidaminococcaceae" "Garrity and Holt 2001" nom. nud. see Family Acidaminococcaceae Marchandin et al. 2010
           8 Family Syntrophomonadaceae Zhao et al. 1993