Order †Plesiadapiformes Simons & Tattersall, 1972 see Suborder Plesiadapiformes Simons & Tattersall, 1972 Superfamily †Microsyopoidea Osborn & Wortman, 1892 Family †Microsyopidae Osborn, 1892 1 Genus †Navajovius Matthew & Granger, 1921 2 Genus †Niptomomys McKenna, 1960