Additionally, 18 proteins which are uniquely found in members of Thermococci, Archaeoglobus and methanogens have been identified, suggesting that these three groups of Archaea may have shared a common...Additionally, 18 proteins which are uniquely found in members of Thermococci, Archaeoglobus and methanogens have been identified, suggesting that these three groups of Archaea may have shared a common relative exclusive of other Archaea. Archaeoglobus are sulfate-reducing archaea, coupling the reduction of sulfate to sulfide with the oxidation of many different organic carbon sources, including complex polymers.