By Melissa Hogenboom14 January 2016
A new species of a marine-dwelling crocodile has been discovered in Tunisia in northern Africa.
It lived about 130 million years ago, at the start of a period called the Cretaceous. At the time dinosaurs dominated the land and huge reptiles ruled the seas.
Its teeth were designed for crushing hard material
The beast has been given the appropriate moniker Machimosaurus rex, which translates as "fighting lizard-king".
It was over 30ft (10m) long, about the size of a large bus. Its skull alone was over 5ft (1.6m) long.
This makes it the largest "thalattosuchian" ever found. The name refers to an extinct group of marine reptiles that were closely related to crocodiles.