Belly has flat rows of ripples that may help the lizards wriggle
M. Spinner et al/ Proceedings of the Royal Society B 2013
A belly carpeted in flattened ridges may help legless lizards slither. Some geckos have only two tiny tabs for legs, so they wriggle and glide like snakes.
These geckos may propel themselves with microscopic corduroy-like ribs on their skin, Marlene Spinner of the University of Kiel in Germany and colleagues suggest October 9 in the Proceedings of the Royal Society B. Unlike geckos with legs, which owe their sticky grip to spines on the skin, the flap-footed lizard Lialis jicari is spine-free where skin skims the ground.
Instead, the reptile carries blunt nubs on the chin and rows of orderly ripples on the stomach, the team discovered by examining freshly shed skin under a microscope. The skin ribs could reduce friction as the animals slide forward.