| No. | 
    Refseq | 
    Organism | 
    Lineage | 
    Assembly Level | 
    
        | 1 | 
        NC_000854.2 | 
        Aeropyrum pernix K1 | 
        Archaea, Crenarchaeota, Thermoprotei, Desulfurococcales, Desulfurococcaceae, Aeropyrum. | 
        Complete | 
    
    
        | 2 | 
        NC_000868.1 | 
        Pyrococcus abyssi GE5 | 
        Archaea, Euryarchaeota, Thermococci, Thermococcales, Thermococcaceae, Pyrococcus. | 
        Complete | 
    
    
        | 3 | 
        NC_000909.1 | 
        Methanocaldococcus jannaschii DSM 2661 | 
        Archaea, Euryarchaeota, Methanococci, Methanococcales, Methanocaldococcaceae, Methanocaldococcus. | 
        Complete | 
    
    
        | 4 | 
        NC_000916.1 | 
        Methanothermobacter thermautotrophicus str. Delta H | 
        Archaea, Euryarchaeota, Methanobacteria, Methanobacteriales, Methanobacteriaceae, Methanothermobacter. | 
        Complete | 
    
    
        | 5 | 
        NC_000917.1 | 
        Archaeoglobus fulgidus DSM 4304 | 
        Archaea, Euryarchaeota, Archaeoglobi, Archaeoglobales, Archaeoglobaceae, Archaeoglobus. | 
        Complete | 
    
    
        | 6 | 
        NC_000961.1 | 
        Pyrococcus horikoshii OT3 | 
        Archaea, Euryarchaeota, Thermococci, Thermococcales, Thermococcaceae, Pyrococcus. | 
        Complete | 
    
    
        | 7 | 
        NC_002607.1 | 
        Halobacterium sp. NRC-1 | 
        Archaea, Euryarchaeota, Halobacteria, Halobacteriales, Halobacteriaceae, Halobacterium. | 
        Complete | 
    
    
        | 8 | 
        NC_002754.1 | 
        Sulfolobus solfataricus P2 | 
        Archaea, Crenarchaeota, Thermoprotei, Sulfolobales, Sulfolobaceae, Sulfolobus. | 
        Complete | 
    
    
        | 9 | 
        NC_003106.2 | 
        Sulfolobus tokodaii str. 7 | 
        Archaea, Crenarchaeota, Thermoprotei, Sulfolobales, Sulfolobaceae, Sulfolobus. | 
        Complete | 
    
    
        | 10 | 
        NC_003413.1 | 
        Pyrococcus furiosus DSM 3638 | 
        Archaea, Euryarchaeota, Thermococci, Thermococcales, Thermococcaceae, Pyrococcus. | 
        Complete | 
    
    
        | 11 | 
        NC_003552.1 | 
        Methanosarcina acetivorans C2A | 
        Archaea, Euryarchaeota, Methanomicrobia, Methanosarcinales, Methanosarcinaceae, Methanosarcina. | 
        Complete | 
    
    
        | 12 | 
        NC_003901.1 | 
        Methanosarcina mazei Go1 | 
        Archaea, Euryarchaeota, Methanomicrobia, Methanosarcinales, Methanosarcinaceae, Methanosarcina. | 
        Complete | 
    
    
        | 13 | 
        NC_005791.1 | 
        Methanococcus maripaludis S2 | 
        Archaea, Euryarchaeota, Methanococci, Methanococcales, Methanococcaceae, Methanococcus. | 
        Complete | 
    
    
        | 14 | 
        NC_006396.1 | 
        Haloarcula marismortui ATCC 43049 chromosome I | 
        Archaea, Euryarchaeota, Halobacteria, Halobacteriales, Halobacteriaceae, Haloarcula. | 
        Complete | 
    
    
        | 15 | 
        NC_006397.1 | 
        Haloarcula marismortui ATCC 43049 chromosome II | 
        Archaea, Euryarchaeota, Halobacteria, Halobacteriales, Halobacteriaceae, Haloarcula. | 
        Complete | 
    
    
        | 16 | 
        NC_006624.1 | 
        Thermococcus kodakarensis KOD1 | 
        Archaea, Euryarchaeota, Thermococci, Thermococcales, Thermococcaceae, Thermococcus. | 
        Complete | 
    
    
        | 17 | 
        NC_007181.1 | 
        Sulfolobus acidocaldarius DSM 639 | 
        Archaea, Crenarchaeota, Thermoprotei, Sulfolobales, Sulfolobaceae, Sulfolobus. | 
        Complete | 
    
    
        | 18 | 
        NC_007355.1 | 
        Methanosarcina barkeri str. fusaro | 
        Archaea, Euryarchaeota, Methanomicrobia, Methanosarcinales, Methanosarcinaceae, Methanosarcina. | 
        Complete | 
    
    
        | 19 | 
        NC_007426.1 | 
        Natronomonas pharaonis DSM 2160 | 
        Archaea, Euryarchaeota, Halobacteria, Halobacteriales, Halobacteriaceae, Natronomonas. | 
        Complete | 
    
    
        | 20 | 
        NC_007681.1 | 
        Methanosphaera stadtmanae DSM 3091 | 
        Archaea, Euryarchaeota, Methanobacteria, Methanobacteriales, Methanobacteriaceae, Methanosphaera. | 
        Complete | 
    
    
        | 21 | 
        NC_007796.1 | 
        Methanospirillum hungatei JF-1 | 
        Archaea, Euryarchaeota, Methanomicrobia, Methanomicrobiales, Methanospirillaceae, Methanospirillum. | 
        Complete | 
    
    
        | 22 | 
        NC_007955.1 | 
        Methanococcoides burtonii DSM 6242 | 
        Archaea, Euryarchaeota, Methanomicrobia, Methanosarcinales, Methanosarcinaceae, Methanococcoides. | 
        Complete | 
    
    
        | 23 | 
        NC_008212.1 | 
        Haloquadratum walsbyi DSM 16790 | 
        Archaea, Euryarchaeota, Halobacteria, Halobacteriales, Halobacteriaceae, Haloquadratum. | 
        Complete | 
    
    
        | 24 | 
        NC_008553.1 | 
        Methanosaeta thermophila PT | 
        Archaea, Euryarchaeota, Methanomicrobia, Methanosarcinales, Methanosaetaceae, Methanosaeta. | 
        Complete | 
    
    
        | 25 | 
        NC_008698.1 | 
        Thermofilum pendens Hrk 5 | 
        Archaea, Crenarchaeota, Thermoprotei, Thermoproteales, Thermofilaceae, Thermofilum. | 
        Complete | 
    
    
        | 26 | 
        NC_008818.1 | 
        Hyperthermus butylicus DSM 5456 | 
        Archaea, Crenarchaeota, Thermoprotei, Desulfurococcales, Pyrodictiaceae, Hyperthermus. | 
        Complete | 
    
    
        | 27 | 
        NC_008942.1 | 
        Methanocorpusculum labreanum Z | 
        Archaea, Euryarchaeota, Methanomicrobia, Methanomicrobiales, Methanocorpusculaceae, Methanocorpusculum. | 
        Complete | 
    
    
        | 28 | 
        NC_009033.1 | 
        Staphylothermus marinus F1 | 
        Archaea, Crenarchaeota, Thermoprotei, Desulfurococcales, Desulfurococcaceae, Staphylothermus. | 
        Complete | 
    
    
        | 29 | 
        NC_009051.1 | 
        Methanoculleus marisnigri JR1 | 
        Archaea, Euryarchaeota, Methanomicrobia, Methanomicrobiales, Methanomicrobiaceae, Methanoculleus. | 
        Complete | 
    
    
        | 30 | 
        NC_009073.1 | 
        Pyrobaculum calidifontis JCM 11548 chromosome | 
        Archaea, Crenarchaeota, Thermoprotei, Thermoproteales, Thermoproteaceae, Pyrobaculum. | 
        Complete | 
    
    
        | 31 | 
        NC_009135.1 | 
        Methanococcus maripaludis C5 | 
        Archaea, Euryarchaeota, Methanococci, Methanococcales, Methanococcaceae, Methanococcus. | 
        Complete | 
    
    
        | 32 | 
        NC_009440.1 | 
        Metallosphaera sedula DSM 5348 | 
        Archaea, Crenarchaeota, Thermoprotei, Sulfolobales, Sulfolobaceae, Metallosphaera. | 
        Complete | 
    
    
        | 33 | 
        NC_009464.1 | 
        Uncultured methanogenic archaeon RC-I | 
        Archaea, Euryarchaeota, environmental samples. | 
        Complete | 
    
    
        | 34 | 
        NC_009515.1 | 
        Methanobrevibacter smithii ATCC 35061 | 
        Archaea, Euryarchaeota, Methanobacteria, Methanobacteriales, Methanobacteriaceae, Methanobrevibacter. | 
        Complete | 
    
    
        | 35 | 
        NC_009634.1 | 
        Methanococcus vannielii SB | 
        Archaea, Euryarchaeota, Methanococci, Methanococcales, Methanococcaceae, Methanococcus. | 
        Complete | 
    
    
        | 36 | 
        NC_009635.1 | 
        Methanococcus aeolicus Nankai-3 | 
        Archaea, Euryarchaeota, Methanococci, Methanococcales, Methanococcaceae, Methanococcus. | 
        Complete | 
    
    
        | 37 | 
        NC_009637.1 | 
        Methanococcus maripaludis C7 | 
        Archaea, Euryarchaeota, Methanococci, Methanococcales, Methanococcaceae, Methanococcus. | 
        Complete | 
    
    
        | 38 | 
        NC_009712.1 | 
        Candidatus Methanoregula boonei 6A8 | 
        Archaea, Euryarchaeota, Methanomicrobia, Methanomicrobiales, Genera incertae sedis, Candidatus Methanoregula. | 
        Complete | 
    
    
        | 39 | 
        NC_009776.1 | 
        Ignicoccus hospitalis KIN4/I | 
        Archaea, Crenarchaeota, Thermoprotei, Desulfurococcales, Desulfurococcaceae, Ignicoccus. | 
        Complete | 
    
    
        | 40 | 
        NC_009975.1 | 
        Methanococcus maripaludis C6 | 
        Archaea, Euryarchaeota, Methanococci, Methanococcales, Methanococcaceae, Methanococcus. | 
        Complete | 
    
    
        | 41 | 
        NC_010085.1 | 
        Nitrosopumilus maritimus SCM1 | 
        Archaea, Thaumarchaeota, Nitrosopumilales, Nitrosopumilaceae, Nitrosopumilus. | 
        Complete | 
    
    
        | 42 | 
        NC_010364.1 | 
        Halobacterium salinarum R1 | 
        Archaea, Euryarchaeota, Halobacteria, Halobacteriales, Halobacteriaceae, Halobacterium. | 
        Complete | 
    
    
        | 43 | 
        NC_010482.1 | 
        Candidatus Korarchaeum cryptofilum OPF8 | 
        Archaea, Korarchaeota, Candidatus Korarchaeum. | 
        Complete | 
    
    
        | 44 | 
        NC_011529.1 | 
        Thermococcus onnurineus NA1 | 
        Archaea, Euryarchaeota, Thermococci, Thermococcales, Thermococcaceae, Thermococcus. | 
        Complete | 
    
    
        | 45 | 
        NC_011766.1 | 
        Desulfurococcus kamchatkensis 1221n, complete genome. | 
        Archaea, Crenarchaeota, Thermoprotei, Desulfurococcales, Desulfurococcaceae, Desulfurococcus | 
        Complete | 
    
    
        | 46 | 
        NC_011832.1 | 
        Candidatus Methanosphaerula palustris E1-9c | 
        Archaea, Euryarchaeota, Methanomicrobia, Methanomicrobiales, Genera incertae sedis, Methanosphaerula. | 
        Complete | 
    
    
        | 47 | 
        NC_012028.1 | 
        Halorubrum lacusprofundi ATCC 49239 chromosome 2 | 
        Archaea, Euryarchaeota, Halobacteria, Halobacteriales, Halobacteriaceae, Halorubrum. | 
        Complete | 
    
    
        | 48 | 
        NC_012029.1 | 
        Halorubrum lacusprofundi ATCC 49239 chromosome 1 | 
        Archaea, Euryarchaeota, Halobacteria, Halobacteriales, Halobacteriaceae, Halorubrum. | 
        Complete | 
    
    
        | 49 | 
        NC_012588.1 | 
        Sulfolobus islandicus M.14.25 | 
        Archaea, Crenarchaeota, Thermoprotei, Sulfolobales, Sulfolobaceae, Sulfolobus. | 
        Complete | 
    
    
        | 50 | 
        NC_012589.1 | 
        Sulfolobus islandicus L.S.2.15 | 
        Archaea, Crenarchaeota, Thermoprotei, Sulfolobales, Sulfolobaceae, Sulfolobus. | 
        Complete | 
    
    
        | 51 | 
        NC_012622.1 | 
        Sulfolobus islandicus Y.G.57.14 | 
        Archaea, Crenarchaeota, Thermoprotei, Sulfolobales, Sulfolobaceae, Sulfolobus. | 
        Complete | 
    
    
        | 52 | 
        NC_012623.1 | 
        Sulfolobus islandicus Y.N.15.51 | 
        Archaea, Crenarchaeota, Thermoprotei, Sulfolobales, Sulfolobaceae, Sulfolobus. | 
        Complete | 
    
    
        | 53 | 
        NC_012632.1 | 
        Sulfolobus islandicus M.16.27 | 
        Archaea, Crenarchaeota, Thermoprotei, Sulfolobales, Sulfolobaceae, Sulfolobus. | 
        Complete | 
    
    
        | 54 | 
        NC_012726.1 | 
        Sulfolobus islandicus M.16.4 | 
        Archaea, Crenarchaeota, Thermoprotei, Sulfolobales, Sulfolobaceae, Sulfolobus. | 
        Complete | 
    
    
        | 55 | 
        NC_012804.1 | 
        Thermococcus gammatolerans EJ3 | 
        Archaea, Euryarchaeota, Thermococci, Thermococcales, Thermococcaceae, Thermococcus. | 
        Complete | 
    
    
        | 56 | 
        NC_012883.1 | 
        Thermococcus sibiricus MM 739 | 
        Archaea, Euryarchaeota, Thermococci, Thermococcales, Thermococcaceae, Thermococcus. | 
        Complete | 
    
    
        | 57 | 
        NC_013156.1 | 
        Methanocaldococcus fervens AG86 | 
        Archaea, Euryarchaeota, Methanococci, Methanococcales, Methanocaldococcaceae, Methanocaldococcus. | 
        Complete | 
    
    
        | 58 | 
        NC_013158.1 | 
        Halorhabdus utahensis DSM 12940 chromosome | 
        Archaea, Euryarchaeota, Halobacteria, Halobacteriales, Halobacteriaceae, Halorhabdus. | 
        Complete | 
    
    
        | 59 | 
        NC_013202.1 | 
        Halomicrobium mukohataei DSM 12286 | 
        Archaea, Euryarchaeota, Halobacteria, Halobacteriales, Halobacteriaceae, Halomicrobium. | 
        Complete | 
    
    
        | 60 | 
        NC_013407.1 | 
        Methanocaldococcus vulcanius M7 | 
        Archaea, Euryarchaeota, Methanococci, Methanococcales, Methanocaldococcaceae, Methanocaldococcus. | 
        Complete |