奇古菌门门

Nitrososphaeria is a class of Archaea under the phylum Thermoproteota. The first species, Cenarchaeum symbiosum, was discovered in 1996 and was found to have a genome distinct from other known archaea at the time; hence, it was classified as a separate phylum. A decade later, three ammonia-oxidizing archaea were described, Nitrosopumilus maritimus, Nitrososphaera viennensis, and Nitrososphaera gargensis. Genome analysis in 2010 revealed that C. symbiosum and the three archaea are genetically of the same group.