The Crocodylia sarcosuchus was the prehistoric ancestor of today's crocodiles, roaming the rivers of what is now Africa and growing up to 40 feet in length (twice as large as the biggest "modern" crocodile on record). An adult would have weighed approximately 8,000kg, which is ten times the average weight of a modern adult crocodile. Fossils of these species are rare, and in particular, the skull is highly vulnerable to the ravages of time, the example here offered being particularly well-preserved.