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 Clostridia Rainey 2010 Order Thermoanaerobacterales Wiegel 2010 Family Thermoanaerobacteraceaeᵀ Wiegel 2010 [Genus Thermoanaerobium Zeikus et al. 1983] see Genus Thermoanaerobacter Wiegel and Ljungdahl 1982 [Thermoanaerobium brockiiᵀ Zeikus et al. 1983] see Thermoanaerobacter brockii subsp. brockii (Zeikus et al. 1983) Cayol et al. 1995