English: Gerhard Heilmann's comparative illustrations of the feet and scale shields of various extant birds and reptiles: green lizard (1), viviparous lizard (2), alligator (3), hooded crow (4), pheasant (5), black grouse (6), and ptarmigan (7).
Датум
Извор
The Danish book Vor Nuvaerende Viden om Fuglenes Afstamming
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|Description = Gerhard Heilmann's comparative illustrations of the feet and scale shields of various extant birds and reptiles: green lizard (1), viviparous lizard (2), alligator (3), hooded crow (4), pheasant (5), black grouse (6), and