Imperium naturæ C. Linnaeus, 1758 - nature
   Mundus Plinius - physical world
     naturalia - natural bodies
       Regnum Animale C. Linnaeus, 1758 - animal kingdom see Kingdom Animalia Linnaeus, 1758
         Class Mammalia Linnaeus, 1758 - mammals
           Pinnata Linnaeus, 1758 see Class Mammalia Linnaeus, 1758
             Order Cete Linnaeus, 1758 see Order Cetartiodactyla Montgelard, Catzeflis & Douzery, 1997
               Genus Monodon Linnaeus, 1758 - narwhal
                 1 Monodon monoceros Linnaeus, 1758 - narwhal