A "saber-toothed cat in armor" and a pancake-shaped predator are among the strange crocodile cousins whose bones have been found beneath the windswept dunes of the Sahara, archaeologists say.

The diverse menagerie of reptiles ruled Gondwana—a landmass that later broke up into the southern continents—about a hundred million years ago, during the Cretaceous period.

"There's an entire croc world brewing in Africa that we really had only an inkling about before," said Paul Sereno, a paleontologist at the University of Chicago and leader of a new study.

"We knew about SuperCroc, the titan of all crocs, but we didn't have quite an idea of what existed in the shadows of the Cretaceous," he said.

Ancient crocodile cousins—called crocodilyforms—were not widespread in the Northern Hemisphere.