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. 2024
             Kingdom Bacillatiᵀ (Gibbons and Murray 1978) Oren and Göker 2024
               Phylum Bacillotaᵀ Gibbons and Murray 2021
                 Class Bacilliᵀ Ludwig et al. 2010
                   Order Caryophanalesᵀ Peshkoff 1939 (Approved Lists 1980)
                     Family Bacillaceae Fischer 1895 (Approved Lists 1980)
                       Genus Geobacillus Nazina et al. 2001
                         01 Geobacillus caldoxylosilyticus (Ahmad et al. 2000) Fortina et al. 2001
                         02 Geobacillus galactosidasius Poli et al. 2012
                         03 Geobacillus gargensis Nazina et al. 2004
                         04 Geobacillus jurassicus Nazina et al. 2005
                         05 Geobacillus kaustophilus (Priest et al. 1989) Nazina et al. 2001
                         06 Geobacillus lituanicus Kuisiene et al. 2004
                         07 Geobacillus stearothermophilus (Donk 1920) Nazina et al. 2001
                         08 Geobacillus subterraneus Nazina et al. 2001
                         09 Geobacillus thermantarcticus (Nicolaus et al. 2002) Coorevits et al. 2012
                         10 Geobacillus thermocatenulatus (Golovacheva et al. 1991) Nazina et al. 2001
                         11 Geobacillus thermodenitrificans (Manachini et al. 2000) Nazina et al. 2001
                         12 Geobacillus thermoglucosidasius (Suzuki et al. 1984) Nazina et al. 2001
                         13 Geobacillus thermoleovorans (Zarilla and Perry 1988) Nazina et al. 2001
                         14 Geobacillus toebii Sung et al. 2002
                         15 Geobacillus uzenensis Nazina et al. 2001
                         16 Geobacillus vulcani (Caccamo et al. 2000) Nazina et al. 2004