An artistic reconstruction of Tetrapodophis amplectus in an aquatic environment. (Julius Csotonyi) In 2015, paleontologists announced a stunning discovery. Preserved in Cretaceous rock from Brazil was the complete skeleton of a beast resembling a snake, but with one significant addition: four tiny, almost vestigial legs. This marked something of a paleontological 'holy grail'. The beast, which they named Tetrapodophis amplectus, was the missing link between snakes and lizards. There's just one problem. According to a new analysis of the remains, Tetrapodophis (from the Greek, meaning "four-legged snake") is not a snake at all, but a species of extinct marine lizard...