"Korarchaeota" are the least derived of all
Archaea. Unfortunately, we know very little about this group. Representatives of the "Korarchaeota" have thus far been identified only from a single hot spring, Obsidian Pool, in Yellowstone National Park, and the group is not formally recognized taxonomically (thus the use of quotes around the name). However, mixed laboratory cultures of "Korarchaeota" exist that clearly indicate that they are hyperthermophiles, as would be expected of prokaryotes close to the root of the tree of
Archaea. Further progress on this interesting group is anticipated and may yield secrets about the early Earth and early life forms.
Taken from the text Brock Biology of Microorganisms (10th ed.). Madigan, M.T., Martinko, J.M., and Parker, J. 2003. Prentice Hall. 470p.