Titanoboa, the giant snake

Titanoboa cerrejonensis is known from vertebrae and ribs found in the Cerrejon coal mine in La Guajira, Colombia, one of the largest open pit coal mines in the world. Jonathan Bloch of the Florida Museum, Carlos Jaramillo of the Smithsonian Tropical Research Institute and Jason Head, then at Toronto, described it in Nature in 2009. The beds date to roughly 60 to 58 million years ago, only a few million years after the asteroid impact.

Scaling from the size of its backbone, the team estimated a length of about 13 metres and a mass near 1,135 kilograms, a snake as heavy as a small car and far larger than any living one. It was a member of the boa family and probably ate big fish and crocodile relatives, since it lived alongside giant turtles and freshwater crocodilians in a swampy tropical forest. Because snakes and other reptiles take their body temperature from their surroundings, the authors argued that so large a snake needed an average annual temperature of about 30 to 34 degrees Celsius, warmer than the modern tropics. Other scientists dispute how precisely a snake can serve as a thermometer, but the fossil shows how quickly big reptiles reoccupied top predator roles after the dinosaurs.