Systema naturæ - nature Universum - universe see [unranked] Mundus Plinius naturalia - natural bodies Regnum Animale nom. inval. - animal kingdom see Kingdom Animalia Linnaeus, 1758 Class Aves Plinius, nom. inval. - birds see Class Aves Linnaeus, 1758 Order Anseres nom. inval. see Order Anseres Linnaeus, 1758 Genus Mergus nom. inval. see Genus Mergus Linnaeus, 1758 Merganser nom. inval.