History of discovery of the first hyperthermophiles.

Hyperthermophiles, growing optimally at 80 degrees C and above had been discovered in 1981. They represent the upper temperature border of life and are found within high temperature environments. In their basically anaerobic surroundings, they gain energy mainly by inorganic redox reactions. Within the phylogenetic tree, hyperthermophiles occupy all the short deep branches closest to the root. The earliest archaeal phylogenetic lineage is represented by the extremely tiny members of the novel kingdom of Nanoarchaeota.