Clade Cynodontia Owen 1861 [Gauthier, Kluge & Rowe 1988]
   Clade Epicynodonts Hopson & Kitching 2001
     Clade Eucynodontia Kemp 1982 [Rowe 1993]
       Clade Mammaliamorpha Rowe 1988
         Class Mammalia Linnaeus, 1758 - mammals
           Clade Trechnotheria McKenna 1975
             Clade Cladotheria McKenna 1975
               Clade Zatheria McKenna 1975
                 Subclass Boreosphenida Luo, Cifelli & Kielan-Jaworowska, 2001 - tribotherians see Clade Boreosphenida Luo, Cifelli & Kielan-Jaworowska 2001
                   1 Order †Aegialodontia Butler, 1978
                   2 Infraclass Metatheria Huxley, 1880
                   3 Infraclass Eutheria Gill, 1872