Methanosarcinales is an order of Archaea in the class Methanomicrobia, phylum Methanobacteriota. The order Methanosarcinales contains both methanogenic and methanotrophic lineages, although the latter have so far no pure culture representatives. Methanotrophic lineages of the order Methanosarcinales were initially abbreviated as ANME to distinguich from aerobic methanotrophic bacteria. Currently, those lineages receive their own names such as Ca. Methanoperedens, Ca. Methanocomedens (ANME-2a), Ca.Methanomarinus (ANME-2b), Ca. Methanogaster (ANME-2c), Ca. Methanovorans (ANME-3). The order contains archaeon with one of the largest genome, Methanosarcina acetivorans C2A, genome size 5,75 Mbp.