prokaryotes - bacteria see Domain Bacteria Woese et al. 1990 Domain "Archaea" Woese et al. 1990 Phylum "Crenarchaeota" Garrity and Holt 2001 [monotypic] Class Thermoprotei Reysenbach 2002 Order Thermoproteales Zillig and Stetter 1982 Family Thermoproteaceae Zillig and Stetter 1982 Genus Pyrobaculum Huber et al. 1988