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?] Phylum "Deltaproteobacteria" Kuever et al., 2006 [polyphyletic] 1 Class Thermodesulfobacteria Hatchikian et al. 2002 [monotypic] 2.1 Class Deltaproteobacteriaᵀ Kuever et al. 2006 2.2 Class Oligoflexia Nakai et al. 2014 [monotypic]