Adriosaurus

Adriosaurus is an extinct genus of aquatic lizard that lived about 95 million years ago. It was snake-like and grew 10 to 12 inches. This is the first fossil record of vestigial limbs in lizards, and gives scientists a glimpse back to the time when terrestrial lizards evolved to be limbless and returned to their watery origins.[3][4]

Cladogram based on Palci and Caldwell (2010a), Caldwell and Palci (2010b)