It's just as well that Titanoboa cerrejonensis went extinct nearly 60 million years ago. A forebear of modern anacondas and boa constrictors, this long-gone snake weighed in at a ton and stretched 45 ft. or more in length far bigger than the biggest snake alive today. It was so big, in fact, that when paleontologists first dug the bones out of an open-pit coal mine in Colombia, they thought they had found a crocodile. Titanoboa made its formal debut in the journal Nature in February. The prehistoric snake is important not just for what it says about snakes but for what it says about climate: to survive at that size, the average equatorial temperature had to have been between 86°F and 93°F, compared with today's 82°F. That could be where our climate is heading in the future. And if it is, the last thing we'll need to worry about is the return of Titanoboa.