[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Domain "Archaea" Woese et al. 1990 stat. inval. see Domain Archaea Woese et al. 2024
     Phylum "Euryarchaeota" Garrity and Holt 2002 stat. inval. see Kingdom Methanobacteriati (Garrity and Holt 2023) Oren and Göker 2024
       Class Thermococci Zillig and Reysenbach 2002
         Order Thermococcales Zillig 1988
           Family Thermococcaceae Zillig 1988
             1 Genus Thermococcus Zillig 1983
             2 Genus Palaeococcus Takai et al. 2000
             3 Genus Pyrococcus Fiala and Stetter 1986