Five exotic crocodiles that lived alongside the dinosaurs 100 million years ago, including one sporting boar-like tusks and another with a duckbill snout, have been discovered in the Sahara.

Unlike their modern cousins, the ancient crocodilians were as agile on land as they were in the water.

They were reptiles like the dinosaurs, but belonged to a completely separate lineage that continues to this day.

The crocodiles once ran and swam across present-day Niger and Morocco, when the region was covered by lush plains and broad rivers.

Scientists found the newly-identified fossils at a number of sites in the Sahara desert. Many were uncovered at one location, lying on the surface of a remote and windswept stretch of rock and dunes.

Expedition leader Professor Paul Sereno, from the University of Chicago, has previously described the largest find, Sarcosuchus imperator, which measured 40 feet and weighed eight tons.