Patterns sculpted by physics: Evolution as revealed by turtle scales
In most vertebrates, skin appendages such as hair, feathers, or scales originate from placodes—small, specialized skin regions whose spatial organization is controlled by well-conserved genetic signals. Crocodiles are an exception: their head scales do not emerge from placodes but result from simple mechanical folding of the growing skin.
In most vertebrates, skin appendages such as hair, feathers, or scales originate from placodes—small, specialized skin regions whose spatial organization is controlled by well-conserved genetic signals. Crocodiles are an exception: their head scales do not emerge from placodes but result from simple mechanical folding of the growing skin.
