Cracked Skin and Crocodile Scales

Head of a juvenile Nile crocodile (Crocodylus niloticus). The irregular polygonal scales on the face and jaws of crocodiles are not controlled genetically. Instead, the patterns are generated through a self-organizational process in which the stiff skin cracks in a tensional stress field as the crocodile grows. Click here for more information.

[Photo: Michel C. Milinkovitch and Adrien Debry]

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Cracked Skin and Crocodile Scales

Researchers have discovered how the scaly skin pattern on crocodile faces and jaws is created. Mammalian hairs, bird feathers, and many reptile scales grow from genetically-controlled processes, but the crocodile’s head scales don’t follow this nearly universal rule. Instead, crocodile face and jaw scales seem to emerge from the physical cracking of skin, which creates distinct, random, non-overlapping polygonal shapes.

Read more about this research from the 29 November issue of Science Express here.

[Image courtesy of Michel C. Milinkovitch; click the image for more information.]

© 2012 American Association for the Advancement of Science. All Rights Reserved.

© 2014 American Association for the Advancement of Science. All Rights Reserved.