Natura - nature
  
 actualia - actual entities
    
 Mundus Plinius - physical world
      
 naturalia - natural bodies
        
 Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
          
 Domain Bacteria Woese et al. 1990 [paraphyletic?]
            
 Superphylum Terrabacteria Battistuzzi et al. 2004
              
 Phylum Firmicutes corrig. Gibbons and Murray 1978 (Approved Lists 1980)
                
 Class Bacilli Ludwig et al. 2010
                  
 Order Bacillalesᵀ Prévot 1953 (Approved Lists 1980)
                    
 0 [Family "Turicibacteraceae"]
 see Family Erysipelotrichaceae Verbarg et al. 2004
                    
 01 Genus Chungangia Kim et al. 2012, incertae sedis [monotypic]
                    
 02 Genus Desulfuribacillus Sorokin et al. 2014, incertae sedis [monotypic]
                    
 03 Genus Exiguobacterium Collins et al. 1984, incertae sedis
                    
 04 Genus Gemella Berger 1960 (Approved Lists 1980), incertae sedis
                    
 05 Genus Geomicrobium Echigo et al. 2010, incertae sedis
                    
 06 Genus Rummeliibacillus Vaishampayan et al. 2009, incertae sedis
                    
 07 Genus Solibacillus Krishnamurthi et al. 2009, incertae sedis [monotypic]
                    
 08 Genus Thermicanus Gößner et al. 2000, incertae sedis [monotypic]
                    
 09.1 Family Bacillaceaeᵀ Fischer 1895 (Approved Lists 1980)
                    
 09.2 Family Planococcaceae Krasil'nikov 1949 (Approved Lists 1980)
                    
 09.2.7 [Family Caryophanaceae Peshkoff 1939 (Approved Lists 1980) [monotypic]]
 see Family Planococcaceae Krasil'nikov 1949 (Approved Lists 1980)
                    
 12 Family Listeriaceae Ludwig et al. 2010
                    
 12.0 [Family "Listeriaceae" Garrity and Holt 2001 nom. nud.]
 see Family Listeriaceae Ludwig et al. 2010
                    
 13 Family Staphylococcaceae Schleifer and Bell 2010
                    
 13.0 [Family "Staphylococcaceae" Schleifer & Bell, 2010]
 see Family Staphylococcaceae Schleifer and Bell 2010
                    
 14 Family Sporolactobacillaceae Ludwig et al. 2010
                    
 14.0 [Family "Sporolactobacillaceae" Ludwig et al., 2010]
 see Family Sporolactobacillaceae Ludwig et al. 2010
                    
 15 Family Paenibacillaceae De Vos et al. 2010
                    
 15.0 [Family "Paenibacillaceae" De Vos et al., 2010]
 see Family Paenibacillaceae De Vos et al. 2010
                    
 16.1 Family Pasteuriaceae Laurent 1890 (Approved Lists 1980) [monotypic]
                    
 16.2 Family Alicyclobacillaceae da Costa and Rainey 2010
                    
 16.2.0 [Family "Alicyclobacillaceae" da Costa & Rainey, 2010]
 see Family Alicyclobacillaceae da Costa and Rainey 2010
                    
 17 Family Thermoactinomycetaceae Matsuo et al. 2006
                    
 17.0 [Family "Thermoactinomycetaceae"]
 see Family Thermoactinomycetaceae Matsuo et al. 2006