The Elrhaz Formation is a geological formation in Niger, West Africa.
Its strata date back to the Early Cretaceous, about 125 to 112 million years ago. Dinosaur remains are among the fossils that have been recovered from the formation, alongside those of multiple species of crocodyliformes.
Gadoufaoua (Tuareg for "the place where camels fear to go") is a site within the Elrhaz Formation (located at ) in the Tenere desert of Niger known for its extensive fossil graveyard. It is where remains of Sarcosuchus imperator, popularly known as SuperCroc, were found (by Paul Sereno in 1997, for example), including vertebrae, limb bones, armor plates, jaws, and a nearly complete skull.
Today, Gadoufaoua is very hot and dry. However, 112 million years ago (based on the sedimentary and fossil record), Gadoufaoua had trees, plants, and wide rivers. The river covered the remains of dead animals, the fossilized remains of which were protected by the drying rivers over millions of years.