A novel coccoid, anaerobic, Fe2+-oxidizing archaeum was isolated from a shallow submarine hydrothermal system at Vulcano, Italy. In addition to ferrous iron, H2 and sulfide served as electron donors. NO3- was used as electron acceptor. In the presence of H2, also S2O32- could serve as electron acceptor. The isolate was a neutrophilic hyperthermophile that grew between 65 degrees C and 95 degrees C. It represents a novel genus among the Archaeoglobales that we name Ferroglobus. The type species is Ferroglobus placidus (DSM 10642).