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 1 Order Clostridialesᵀ Prévot 1953 (Approved Lists 1980) 2 Order Thermoanaerobacterales Wiegel 2010 3 Order Halanaerobiales corrig. Rainey and Zhilina 1995 4 Order Natranaerobiales Mesbah et al. 2007 [monotypic]