[4] The phylogeny of the Nanoarchaeota is anchored by its only cultured representative, Nanoarchaeum equitans, which clusters in a separate evolutionary group than other archaea,[5][6] which have recently been reclassified.

[7] The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN)[8] and the National Center for Biotechnology Information (NCBI).

N. stetteri" Cells of N. equitans are spherical with a diameter of approximately 400 nm,[2] and have a very short and compact DNA sequence with the entire genome containing only 490,885 base pairs.

[6] Because of their unusual ss rRNA sequences, they are difficult to detect using standard polymerase chain reaction methods.

[3]  Genetic evidence for members of the Nanoarchaeota has been discovered to be pervasive in terrestrial hot springs and mesophilic hypersaline habitats using primers created based on the sequence of the 16S rRNA gene of Nanoarchaeum equitans.

[3] In addition, the discovery of ribosomal sequences in photic-zone water samples taken distant from hydrothermal vents raises the possibility that Nanoarchaeota are an ubiquitous and diversified group of Archaea that can live in habitats with a variety of temperatures and geochemical settings.

[24] The majority of recognized metabolic processes, such as the creation of monomers like amino acids, nucleotides, and coenzymes, lack recognizable genes in this organism.