Unusual scales on crocodile heads due to skin growth rate, scientists say

Researchers find that varying stiffness and speeds at which skin grows lead to mechanical' formation of inward folds

It sounds like a conundrum that Rudyard Kipling would have explored in his Just So Stories, but researchers say they have the answer to how crocodiles get the scales on their heads.

Many animals, from turtles to birds, have scales - hard plate-like structures that form on the skin.