Natura - nature actualia - actual entities Mundus Plinius - physical world naturalia - natural bodies ["Animale Regnum" nom. inval. - animal kingdom] see Kingdom Animalia Linnaeus, 1758 [Class "Aves" Plinius, nom. inval. - birds] see Class Aves Linnaeus, 1758 [Order "Picae" nom. inval.] see Order Picae Linnaeus, 1758 [Genus "Buceros" Linnaeus, 1748, nom. inval.] see Genus Buceros Linnaeus, 1758