Spring, S.; Scheuner, C.; Lapidus, A.; Lucas, S.; Rio, T. G. D.; Tice, H.; Copeland, A.; Cheng, J.; Chen, F.   cc-by-3.0

Methanomicrobia is a class of Archaeans. There are 99 species of Methanomicrobia, in 24 genera and 10 families. It includes groups like Methanocellales, Methanomicrobiales, and Methanosarcinales.