A proposed taxonomic revision that would replace the three-*domain classification with one of only two domains, Bacteria and Archaea, an idea first proposed in 1984 by James Lake and colleagues. Eocytes are sulphur-metabolizing, extreme thermophile organisms, placed within the Crenarchaeota in the three-domain taxonomic system, but recent genetic studies have shown eocytes to be very closely related to eukaryotes, suggesting that eukaryotes and Crenarchaeota share a common ancestor. This evidence supports the abandonment of the three-domain classification in favour of a two-domain classification comprising the Eubacteria and Archaea, with the Eukarya contained within the Archaea.
http://fbae.org/2009/FBAE/website/images/pdf/imporatant-publication/Eocyte_Origin_of_Eukaryotic_Cells.pdf. An outline of the eocyte hypothesis.