Nitrospirae is a phylum of bacteria. It contains only one class, Nitrospira, which itself contains one order (Nitrospirales) and one family (Nitrospiraceae). It includes multiple genera, such as Nitrospira, the largest. The first member of this phylum, Nitrospira marina, was discovered in 1985. The second member of this phylum, Thermodesulfovibrio yellowstonii, was discovered in 1994. The third member, Nitrospira moscoviensis, was discovered in 1995.