procaryotes Domain Archaea Woese et al. 1990 Phylum Euryarchaeota Garrity and Holt 2001 Class Methanopyri Garrity and Holt 2001 nom. inval. see Class Methanopyri Garrity and Holt 2002 Order Methanopyrales Huber and Stetter 2001 nom. inval. see Order Methanopyrales Huber and Stetter 2002 1 Family Methanopyraceae Huber and Stetter 2001 nom. inval. see Family Methanopyraceae Huber and Stetter 2002