Methanopyrus is a genus of methanogen, with a single described species, M. kandleri. It is a hyperthermophile, discovered in a black smoker from the Gulf of California at a depth of 2000 m, at temperatures of 80-101 °C. It lives in an hydrogen-carbon dioxide rich environment, and like other methanogens reduces the latter to methane. It is placed among the Euryarchaeota, in its own class.