| argentina | jujuy province | uncultured methanothermococcus sp. | species | 1 | 0 |
| brazil | | uncultured methanococcus sp. | species | 2 | 0 |
| brazil | | uncultured methanothermococcus sp. | species | 1 | 0 |
| china | | methanothermococcus sp. enrichment clone m11 | species | 1 | 0 |
| china | | methanothermococcus sp. enrichment clone m37 | species | 1 | 0 |
| china | | uncultured methanococcus sp. | species | 2 | 0 |
| india | | methanococcus sp. enrichment culture clone cibanicra-21 | species | 1 | 0 |
| india | | methanococcus sp. enrichment culture clone cibanicra-22 | species | 1 | 0 |
| india | | methanococcus sp. enrichment culture clone cibanicra-23 | species | 1 | 0 |
| india | | methanococcus sp. enrichment culture clone cibanicra-24 | species | 1 | 0 |
| india | | methanococcus sp. enrichment culture clone cibanicra-25 | species | 1 | 0 |
| india | | methanococcus sp. enrichment culture clone cibanicra-26 | species | 1 | 0 |
| india | | methanococcus sp. enrichment culture clone cibanicra-27 | species | 1 | 0 |
| india | | methanococcus sp. enrichment culture clone cibanicra-28 | species | 1 | 0 |
| india | | methanococcus sp. enrichment culture clone cibanicra-29 | species | 1 | 0 |
| india | | methanococcus sp. enrichment culture clone cibanicra-30 | species | 1 | 0 |
| india | | methanococcus sp. enrichment culture clone cibanicra-31 | species | 1 | 0 |
| india | | methanococcus sp. enrichment culture clone cibanicra-32 | species | 1 | 0 |
| india | | methanococcus sp. enrichment culture clone cibanicra-33 | species | 1 | 0 |
| india | | methanococcus sp. enrichment culture clone cibanicra-34 | species | 1 | 0 |
| india | | methanococcus sp. enrichment culture clone cibanicra-35 | species | 1 | 0 |
| india | | methanococcus sp. enrichment culture clone cibanicra-36 | species | 1 | 0 |
| india | | methanococcus sp. enrichment culture clone cibanicra-37 | species | 1 | 0 |
| india | | methanococcus sp. enrichment culture clone cibanicra-38 | species | 1 | 0 |
| india | | methanococcus sp. enrichment culture clone cibanicra-mbt10 | species | 1 | 0 |
| india | | methanococcus sp. enrichment culture clone cibanicra-mbt4 | species | 1 | 0 |
| india | | methanococcus vannielii | species | 2 | 0 |
| india | | methanothermococcus thermolithotrophicus | species | 2 | 0 |
| india | | uncultured methanococcus sp. | species | 21 | 0 |
| india | | uncultured methanothermococcus sp. | species | 8 | 0 |
| italy | | methanothermococcus thermolithotrophicus dsm 2095 | no rank | 55 | 0 |
| japan | | methanococcus maripaludis | species | 1 | 0 |
| japan | | methanothermococcus okinawensis | species | 2 | 0 |
| japan | | methanothermococcus okinawensis ih1 | no rank | 1 | 0 |
| japan | okinawa prefecture | methanococcus | genus | 0 | 1 |
| japan | okinawa prefecture | methanothermococcus | genus | 0 | 1 |
| japan | okinawa prefecture | methanothermococcus sp. e1855-m | species | 1 | 0 |
| japan | okinawa prefecture | methanothermococcus sp. pal55-mc | species | 1 | 0 |
| japan | okinawa prefecture | uncultured methanothermococcus sp. | species | 1 | 0 |
| nigeria | | uncultured methanococcus sp. | species | 3 | 0 |
| nigeria | | uncultured methanothermococcus sp. | species | 2 | 0 |
| united states | | methanococcus maripaludis | species | 1 | 0 |
| united states | california | methanococcus | genus | 0 | 1 |
| united states | florida | methanococcus maripaludis | species | 21 | 0 |
| united states | florida | methanococcus voltae | species | 15 | 0 |
| united states | georgia | methanococcus maripaludis | species | 82 | 0 |
| united states | georgia | methanococcus voltae | species | 20 | 0 |
| united states | south carolina | methanococcus maripaludis | species | 1 | 0 |
| united states | wisconsin | methanococcus | genus | 0 | 1 |
| united states | wisconsin | methanococcus maripaludis | species | 6 | 0 |