Class [Mammalia] Linnaeus, 1758 - mammals
   Order †Plesiadapiformes Simons & Tattersall, 1972 see Suborder Plesiadapiformes Simons & Tattersall, 1972
     Superfamily †Microsyopoidea Osborn & Wortman, 1892
       1 Family †Palaechthonidae Szalay, 1969
       2 Family †Microsyopidae Osborn, 1892