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 Thermofilaceae Burggraf et al. 1997 [monotypic] 1 Genus Thermofilum Zillig and Gierl 1983