Class [Mammalia] Linnaeus, 1758 - mammals
  
 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 †Berruvius Russell, 1964
        
 3 Genus †Niptomomys McKenna, 1960
        
 4 Genus †Uintasorex Brown & Rose, 1976
        
 5 Genus †Avenius Russell, Phélizon & Louis, 1992
        
 6 Genus †Microsyops Leidy, 1872
        
 7 Genus †Arctodontomys Gunnell, 1985
        
 8 Genus †Craseops Stock, 1934
        
 9 Genus †Megadelphus Gunnell, 1989