Limbless Tetrapods and Snakes with Legs

A debate is raging among evolutionary biologists about the origins of snakes: did the ancestors of our modern day slippery serpents slither out of the sea or were they always land dwellers. [Greene and Cundall][1] explain the evidence for and against a marine origin for snakes. In particular, the finding of a new, almost complete, Cretaceous snake fossil with well-developed hindlimbs in the Middle East ([ Tchernov et al .][2]) suggests that the ancestors of snakes may have been landlubbers after all. [1]: http://www.sciencemag.org/cgi/content/full/287/5460/1939 [2]: http://www.sciencemag.org/cgi/content/full/287/5460/2010