Which prehistoric snake, Titanoboa, is estimated to have lived about how many million years ago?

Titanoboa is estimated to have lived about 60 million years ago.

This enormous extinct snake lived during the Paleocene Epoch, soon after the end-Cretaceous mass extinction. Fossils were discovered in the Cerrejón Formation of northeastern Colombia, where ancient tropical ecosystems also preserved plants, turtles, and crocodile relatives. The snake was scientifically named Titanoboa cerrejonensis.

Scientists estimate that Titanoboa reached about 12–13 metres and could have weighed more than a tonne. These figures come mainly from fossil vertebrae and comparisons with living boas, so the exact size of individual animals cannot be known. Its body was much larger than that of any living snake.

Titanoboa is often described as the largest snake known from the fossil record, but it was not a dinosaur. It lived millions of years after non-avian dinosaurs disappeared. Its size also helps palaeontologists investigate how temperature and ecosystems may have influenced the body size of ancient cold-blooded animals.