| Name | Class | Order | Family | Genus |
|---|---|---|---|---|
| Methanocaldococcus fervens | Methanococci | Methanococcales | Methanocaldococcaceae | Methanocaldococcus |
| Methanocaldococcus indicus | Methanococci | Methanococcales | Methanocaldococcaceae | Methanocaldococcus |
| Methanocaldococcus infernus | Methanococci | Methanococcales | Methanocaldococcaceae | Methanocaldococcus |
| Methanocaldococcus jannaschii | Methanococci | Methanococcales | Methanocaldococcaceae | Methanocaldococcus |
| Methanocaldococcus villosus | Methanococci | Methanococcales | Methanocaldococcaceae | Methanocaldococcus |
| Methanocaldococcus vulcanius | Methanococci | Methanococcales | Methanocaldococcaceae | Methanocaldococcus |