Universal Root Woese et al. 1990 Universal Root Woese et al. 1990 Universal Root Woese et al. 1990 Archaea Woese et al. 1990 Bacteria (None 2015) Woese et al. 1990 Woese C.R. Kandler O. Wheelis M.L. Towards a natural system of organisms: proposal for the domains Archaea, Bacteria, and Eucarya 1990 87 12 4576 4579 Proceedings of the National Academy of Sciences of the United States of America Proc Natl Acad Sci U S A 0027-8424 1091-6490 10.1073/pnas.87.12.4576 2112744 Schizomycetes von Nägeli 1857 (Approved Lists 1980) Woese C.R. Kandler O. Wheelis M.L. Towards a natural system of organisms: proposal for the domains Archaea, Bacteria, and Eucarya 1990 87 12 4576 4579 Proceedings of the National Academy of Sciences of the United States of America Proc Natl Acad Sci U S A 0027-8424 1091-6490 10.1073/pnas.87.12.4576 2112744 This unnamed taxon has no rank and serves as the root of the universal phylogenetic tree proposed by Woese et al. 1990.