Crocodile head scales are not developmental units but emerge from physical cracking

Michel C. Milinkovitch, Liana Manukyan, Adrien Debry, Nicolas Di-Poï, Samuel Martin, Daljit Singh, Dominique Lambert, Matthias Zwicker

Research output: Contribution to journalArticlepeer-review


Various lineages of amniotes display keratinized skin appendages (feathers, hairs, and scales) that differentiate in the embryo from genetically controlled developmental units whose spatial organization is patterned by reaction-diffusion mechanisms (RDMs). We show that, contrary to skin appendages in other amniotes (as well as body scales in crocodiles), face and jaws scales of crocodiles are random polygonal domains of highly keratinized skin, rather than genetically controlled elements, and emerge from a physical self-organizing stochastic process distinct from RDMs: cracking of the developing skin in a stress field. We suggest that the rapid growth of the crocodile embryonic facial and jaw skeleton, combined with the development of a very keratinized skin, generates the mechanical stress that causes cracking.

Original languageEnglish
Pages (from-to)78-81
Number of pages4
JournalScience (New York, N.Y.)
Issue number6115
Publication statusPublished - 4 Jan 2013


Dive into the research topics of 'Crocodile head scales are not developmental units but emerge from physical cracking'. Together they form a unique fingerprint.

Cite this