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
           Quadrupedia Linnaeus, 1758 see Class Mammalia Linnaeus, 1758
             Order Glires Linnaeus, 1758 see Superorder Glires Linnaeus, 1758
               Genus Sciurus Linnaeus, 1758 - tree squirrels
                 1 Sciurus vulgaris Linnaeus, 1758 - Eurasian red squirrel
                 2 Sciurus niger Linnaeus, 1758 - eastern fox squirrel
                 3 Sciurus cinereus Linnaeus, 1758 see Sciurus niger Linnaeus, 1758
                 4 Sciurus flavus Linnaeus, 1758, nom. dub.
                 5 Sciurus getulus Linnaeus, 1758 see Atlantoxerus getulus (C. Linnaeus, 1758)
                 6 Sciurus ſtriatus Linnaeus, 1758 see Tamias striatus (C. Linnaeus, 1758)
                 7 Sciurus volans Linnaeus, 1758, nom. illeg. see Pteromys volans (C. Linnaeus, 1758)