When we think about gigantic extinct reptiles we usually think of the Mesozoic Era, the period between about 248 million and 65 million years ago when dinosaurs, pterosaurs, plesiosaurs, mosasaurs and ichthyosaurs inhabited the land and seas. There have however been a few colossal reptiles that have lived more recently - Varanus priscus (usually known as "Megalania prisca"), which was a gigantic monitor lizard that lived in Australia, Pristichampus, which was a terrestrial cursorial (running) crocodile, and a gigantic snake that lived in South America, known as "Titanoboa cerrejonensis".

Titanoboa cerrejonensis lived in what is today Columbia, about 60 million to 58 million years ago. At the time that this giant snake, the region was a tropical rainforest, and it is also believed that the Earth was warmer, and that may have contributed to the snake's colossal size.

It's amazing just how big Titanoboa cerrejonensis was. The largest species of snake that is alive today, Python reticulatus, grows to a maximum of about 32 feet (10 meters) long. Titanoboa was considerably larger, and much much thicker and heavier - it grew up to 43 feet (15 meters) long, had a diameter of around 3 feet (1 meter), and probably weighed over 1 ton.

Titanoboa likes its modern relatives in the boa family was a non-venomous snake. Instead it hunted by wrapping itself around its victims, and constricting them to death. While modern boas typically eat small mammals and birds and perhaps lizards, Titanoboa would have gone for larger prey animals - it is likely that crocodiles and giant turtles were on its menu.