Mammaliaformes Rowe 1988, nom. cl. inval. see Clade Mammaliaformes Rowe 1988 [Rowe 2020]
Period: Late Triassic - Present [237 Mya - present]; Status: extant
   [crown] Class Mammalia Linnaeus, 1758 - mammals
  Period: Late Triassic - Present [237 Mya - present]; Status: extant
     Subclass Theriiformes Rowe, 1988 see Division Theriiformes Rowe, 1988
    Period: Late Triassic - Present [237 Mya - present]; Status: extant
       Infraclass Holotheria Wible, Rougier, Novacek, McKenna & Dashzeveg, 1995 see Clade Holotheria Wible, Rougier, Novacek, McKenna & Dashzeveg 1995
      Period: Late Triassic - Present [237 Mya - present]; Status: extant
         Superlegion Trechnotheria McKenna, 1975 see Clade Trechnotheria McKenna 1975
        Period: Early Jurassic - Present [201.3 Mya - present]; Status: extant
           Legion Cladotheria McKenna, 1975 see Clade Cladotheria McKenna 1975
          Period: Middle Jurassic - Present [174.1 Mya - present]; Status: extant
             Sublegion Zatheria McKenna, 1975 see Clade Zatheria McKenna 1975
            Period: Middle Jurassic - Present [174.1 Mya - present]; Status: extant
               Infralegion Tribosphenida McKenna, 1975 see Subclass Boreosphenida Luo, Cifelli & Kielan-Jaworowska, 2001
              Period: Early Cretaceous - Present [145 Mya - present]; Status: extant
                 [crown] Supercohort Theria Parker & Haswell, 1897 - therians see Subclass Theria Parker & Haswell, 1897
                Period: Early Cretaceous - Present [145 Mya - present]; Status: extant
                   Cohort Placentalia Owen, 1837 - placentals
                  Period: Early Cretaceous - Present [145 Mya - present]; Status: extant
                     Magnorder Epitheria McKenna, 1975 see Cohort Placentalia Owen, 1837
                    Period: Early Cretaceous - Present [145 Mya - present]; Status: extant
                       Superorder Preptotheria McKenna, 1975
                      Period: Late Cretaceous - Present [100.5 Mya - present]; Status: extant
                         Grandorder Ungulata Linnaeus, 1766
                        Period: Late Cretaceous - Present [100.5 Mya - present]; Status: extant
                           Mirorder Eparctocyona McKenna, 1975
                          Period: Early Paleocene - Present [66 Mya - present]; Status: extant
                             Order Cete Linnaeus, 1758 see Order Cetartiodactyla Montgelard, Catzeflis & Douzery, 1997
                            Period: Early Paleocene - Present [66 Mya - present]; Status: extant
                               Suborder Cetacea Brisson, 1762 - cetaceans see Infraorder Cetacea Brisson, 1762
                              Status: extant
                                 Infraorder Autoceta Haeckel, 1866
                                Status: extant
                                   Parvorder Mysticeti Cope, 1891 - whalebone whales
                                  Status: extant
                                     Family †Aetiocetidae Emlong, 1966
                                    Distribution: Nearctic/western North America; Period: Late Oligocene [28.1 - 23.03 Mya]; Status: fossil
                                       Genus †Aetiocetus Emlong, 1966
                                      Status: fossil