21 May 2008
Snake with two legs
A 92 million-year-old Cretaceous snake preserved in Lebanese limestone has been found to have two legs. One leg was visible on the surface of the slab; confirmation of the opposite leg required xray imaging. Only a few bipedal snakes have been found. Further study of this one may help answer the question of whether snakes evolved from marine reptiles, or from terrestrial lizards which began burrowing in the earth and lost forearms first (like this snake), and hind legs later.
"Some of the more primitive modern snakes, such as boas and pythons [show] evidence of their legged ancestry - tiny "spurs" sited near their ends, which today are used as grippers during sex."