Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         [crown] 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 Clostridia Rainey 2010
                   Order Clostridialesᵀ Prévot 1953 (Approved Lists 1980)
                     Family Peptostreptococcaceae Ezaki 2010
                       1.1 Genus Sporacetigenium Chen et al. 2006 [monotypic]
                       1.2 Genus Tepidibacter Slobodkin et al. 2003
                       2.1 Genus Peptostreptococcusᵀ Kluyver and van Niel 1936 (Approved Lists 1980)
                       2.2 Genus Filifactor Collins et al. 1994