Procaryotic Genera Domain "Archaea" Woese et al. 1990 Phylum Euryarchaeota Garrity and Holt 2001 Class Methanopyri Garrity and Holt 2001 nom. inval. [monotypic] see Class Methanopyri Garrity and Holt 2002 Order Methanopyralesᵀ Huber and Stetter 2001 nom. inval. [monotypic] see Order Methanopyrales Huber and Stetter 2002 Family Methanopyraceae Huber and Stetter 2001 nom. inval. [monotypic] see Family Methanopyraceae Huber and Stetter 2002 Genus Methanopyrusᵀ Kurr et al. 1992