ClassClostridia
| Taxon: | Rank: |
| Clostridiales | order |
| Desulfitibacterales | order |
| Eubacteriales | order |
| Halanaerobiales | order |
| Lachnospirales | order |
| Natranaerobiales | order |
| Oscillospirales | order |
| Peptostreptococcales | order |
| Thermoanaerobacterales | order |
| Thermosediminibacterales | order |
| Tissierellales | order |