Hyperthermophiles (genus)
Euryarchaeota
Killed by oxygen gas
Methanogens
Hyperthermophiles in hot sulfur springs, volcanic vents, & cold ocean waters (genus)
Crenarchaeota
Methanogens (genus)
Euryarchaeota
Requires oxygen gas for metabolism
Halophiles
Extreme Halophiles (genus)
Euryarchaeota