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 Aves Linnaeus, 1758 - birds see Subclass Aves Linnaeus, 1758
           Order Gallinae Linnaeus, 1758
             Genus Tetrao Linnaeus, 1758
               01 Tetrao urogallus Linnaeus, 1758 - western capercaillie
               02 Tetrao tetrix Linnaeus, 1758 - black grouse see Lyrurus tetrix (Linnaeus, 1758)
               03 Tetrao canadensis Linnaeus, 1758 see Falcipennis canadensis (Linnaeus, 1758)
               04 Tetrao lagopus Linnaeus, 1758 see Lagopus lagopus (Linnaeus, 1758)
               05 Tetrao phasianellus Linnaeus, 1758 see Tympanuchus phasianellus (Linnaeus, 1758)
               06 Tetrao cupido Linnaeus, 1758 see Tympanuchus cupido (Linnaeus, 1758)
               07 Tetrao bonasia Linnaeus, 1758 see Bonasa bonasia (C. Linnaeus, 1758)
               08 Tetrao rufus Linnaeus, 1758 see Alectoris rufa (Linnaeus, 1758)
               09 Tetrao perdix Linnaeus, 1758 see Perdix perdix (Linnaeus, 1758)
               10 Tetrao virginianus Linnaeus, 1758 see Colinus virginianus (Linnaeus, 1758)
               11 Tetrao marilandicus Linnaeus, 1758
               12 Tetrao orientalis Linnaeus, 1758 see Pterocles orientalis (Linnaeus, 1758)
               13 Tetrao coturnix Linnaeus, 1758 see Coturnix coturnix (Linnaeus, 1758)