Open water swimmers dislike all kinds of jellyfish and they rightly fear sharks and sea snakes, and some even whales if they get too close.

And in others areas in the open water swimming world, open water swimmers have to be aware of orcas, leopard seals and crocodiles.

When an open water swimmer looks closely at a crocodile’s cranium, they see thick scales covering their heads.

Researchers led by evolutionary biologist Michel Milinkovitch of the University of Geneva in Switzerland, who have assumed that the deep lines in the face and jaws of crocodiles marked the boundaries between thick scales, recently found out that the lines are actually simple physical cracks on the head.

“I was really surprised by these chaotic patterns of scales when I looked closely at the crocodile’s head. There were all different sizes and different shapes. Comparing the left and the right, they were very different, and comparing different individuals, they were also very different.”

Milinkovitch found that in late embryonic development, grooves began to appear in the thick skin covering the crocodile’s head. And those cracks continue getting deeper and thicker, remaining for life.

Who knew?

Now we all do.

Copyright © 2012 by World Open Water Swimming Association