A supergroup of archaea named after the initials of four of its member phyla: the Thaumarchaeota, Aigarchaeota, Crenarchaeota, and Korarchaeota. The phylogenetic identity and relationships of these and other prokaryote lineages within the TACK supergroup have been established largely on the basis of metagenomic analysis of environmental samples of DNA taken from sediments, seawater, and other sources. TACK members are regarded as being more closely related to each other than to the other major groups of archaea, the Euryarchaetoa and the DPANN supergroup.