Mammaliaformes Rowe 1988
Ref: M.C. McKenna & S.K. Bell, 1997: 511; Count: [g†g] 1c;24o;125f;1081g; ‡1o;6f;43g; †24o;301f;4057g;1s
   [crown] Class Mammalia Linnaeus, 1758 - mammals
  Ref: M.C. McKenna & S.K. Bell, 1997: 35; Count: [g†g] 24o;125f;1081g; ‡1o;6f;43g; †21o;294f;4034g;1s
     Subclass Theriiformes Rowe, 1988 see Division Theriiformes Rowe, 1988
    Ref: M.C. McKenna & S.K. Bell, 1997: 36 [new rank]; Count: [g†g] 22o;123f;1078g; ‡1o;6f;43g; †21o;294f;4031g;1s
       Infraclass Holotheria Wible, Rougier, Novacek, McKenna & Dashzeveg, 1995 see Clade Holotheria Wible, Rougier, Novacek, McKenna & Dashzeveg 1995
      Ref: M.C. McKenna & S.K. Bell, 1997: 43 [new rank]; Count: [g†g] 22o;123f;1078g; ‡1o;6f;43g; †20o;277f;3936g;1s
         Superlegion Trechnotheria McKenna, 1975 see Clade Trechnotheria McKenna 1975
        Ref: M.C. McKenna & S.K. Bell, 1997: 43 [new position]; Count: [g†g] 22o;123f;1078g; ‡1o;6f;43g; †20o;274f;3932g
           Legion Cladotheria McKenna, 1975 see Clade Cladotheria McKenna 1975
          Ref: M.C. McKenna & S.K. Bell, 1997: 45; Count: [g†g] 22o;123f;1078g; ‡1o;6f;43g; †18o;269f;3910g
             Sublegion Zatheria McKenna, 1975 see Clade Zatheria McKenna 1975
            Ref: M.C. McKenna & S.K. Bell, 1997: 48; Count: [g†g] 22o;123f;1078g; ‡1o;6f;43g; †16o;262f;3884g
               Infralegion Tribosphenida McKenna, 1975 see Subclass Boreosphenida Luo, Cifelli & Kielan-Jaworowska, 2001
              Ref: M.C. McKenna & S.K. Bell, 1997: 48 [new rank]; Count: [g†g] 22o;123f;1078g; ‡1o;6f;43g; †16o;258f;3877g
                 [crown] Supercohort Theria Parker & Haswell, 1897 - therians see Subclass Theria Parker & Haswell, 1897
                Ref: M.C. McKenna & S.K. Bell, 1997: 49 [new rank]; Count: [g†g] 22o;123f;1078g; ‡1o;6f;43g; †16o;256f;3874g
                   Cohort Placentalia Owen, 1837 - placentals
                  Ref: M.C. McKenna & S.K. Bell, 1997: 80 [new rank]; Count: [g†g] 17o;108f;1005g; ‡1o;5f;40g; †12o;218f;3610g
                     Magnorder Xenarthra Cope, 1889 - xenarthrans see Superorder Xenarthra Cope, 1889
                    Ref: M.C. McKenna & S.K. Bell, 1997: 82 [new rank]; Count: [g†g] 2o;5f;13g; ‡1f;5g; †10f;203g
                       Order Pilosa Flower, 1883 - sloths
                      Ref: M.C. McKenna & S.K. Bell, 1997: 91 [new position]; Count: [g†g] 4f;5g; ‡1f;4g; †5f;95g
                         Suborder Phyllophaga Owen, 1842 see Suborder Folivora Delsuc, Catzeflis, Stanhope & Douzery, 2001
                        Ref: M.C. McKenna & S.K. Bell, 1997: 93; Count: [g†g] 2f;2g; ‡1f;4g; †4f;86g
                           Infraorder Megatheria McKenna & Bell, 1997
                          Ref: M.C. McKenna & S.K. Bell, 1997: 96 [new taxon]; Count: -
                             Superfamily Megatherioidea Gray, 1821
                            Ref: M.C. McKenna & S.K. Bell, 1997: 96 [new position]; Count: [g†g] 1f;1g; ‡1f;4g; †53g
                               Family Megalonychidae Gervais, 1855 - West Indian sloths and two-toed tree sloths
                              Ref: M.C. McKenna & S.K. Bell, 1997: 99; Count: [g†g] 1g; ‡2g; †25g
                                 1 Genus †Imagocnus MacPhee & Iturralde-Vinent, 1994
                                Ref: M.C. McKenna & S.K. Bell, 1997: 99; Count: -
                                 2 Subfamily ‡Ortotheriinae Ameghino, 1889
                                Ref: M.C. McKenna & S.K. Bell, 1997: 99; Count: [g†g] ‡1g‡‡11g
                                 3 Subfamily Megalonychinae Gervais, 1855
                                Ref: M.C. McKenna & S.K. Bell, 1997: 100; Count: [g†g] 1g; ‡1g; †13g