After the extinction of the dinosaurs 65m years ago, new giants evolved to terrorise life on Earth: snakes as long as a bus and as wide as a door. On Thursday an international scientific team will announce in the journal Nature the discovery of Titanoboa, the largest snake that has ever lived. Its fossils were found in the Cerrejen coal mines of Colombia. Titanoboa was a constrictor like today’s boas and anacondas, preying on crocodiles and giant turtles about 60m years ago in what was then a steamy tropical rainforest. At a conservative estimate it grew 13 metres long and...