Kingdom Animalia Linnaeus, 1758 - animals
   Phylum Craniata Linnaeus, 1758 see Subphylum Craniata auct.
     Class Mammalia Linnaeus, 1758 - mammals
       Subclass Theria Parker & Haswell, 1897
         Infraclass Placentalia Owen, 1837 see Cohort Placentalia Owen, 1837
           Order Sirenia Gill, 1872 - sea cows
             1 Family Dugongidae Gray, 1821 - dugong and sea cow
             2 Family Trichechidae Gill, 1872 - manatees