Wednesday, July 2, 2025 at 10 p.m. on KPBS TV / Stream now with KPBS Passport + Encore Sunday, July 7 at 10 p.m. on KPBS 2. A mining operation in Cerrejon, Northern Colombia, opened a window onto a previously unknown period of the earth’s history and a world teeming with giant creatures emerged. The biggest of all was Titanoboa a 43-foot snake, the largest that ever lived. But new discoveries in Cerrejon suggest that Titanoboa’s rule was challenged by a giant crocodilian.