The Flaming Cliffs

Where the first dinosaur eggs were found, in 1923

The Flaming Cliffs are a stretch of red sandstone cliffs and spires in the Gobi Desert of Ömnögovi Province, Mongolia, known locally as Bayanzag, rich in saxaul, or Ulaan Ereg, the red cliffs. The American palaeontologist Roy Chapman Andrews gave them their English name in the 1920s for the way the rock glows red and orange, above all at sunset. They expose rocks of the Djadochta Formation, and they are where the world learned that dinosaurs laid eggs in nests.

Andrews of the American Museum of Natural History set out for the Gobi in 1921 hoping to find where early humans had evolved. From 1921 to 1930 his Central Asiatic Expeditions, some 40 people travelling by camel and early motor car, combed an area 3,200 by 1,600 kilometres. They came on their first dinosaur bones in 1922 almost by accident, when a crew member who had wandered off found Protoceratops. The next year George Olsen told the others he had found dinosaur eggs. Andrews wrote that they doubted him until they saw the brown, striated shell poking out of the sandstone and had to admit that eggs are eggs. A nest that looked like three eggs held 25.

The eggs were credited to Protoceratops, the commonest dinosaur at the site. Then the bones of a new birdlike dinosaur turned up on a nest, and it was named Oviraptor, the egg thief, on the assumption that it had died robbing it. The truth took about 70 years. In 1993 Mark Norell and Michael Novacek of the museum found eggs at Ukhaa Tolgod with embryos inside that matched Oviraptor, identical in size, shape, ornament and microstructure to the 1923 eggs. The supposed thief had died brooding her own clutch, the first proof that non-avian dinosaurs sat on nests like birds. The cliffs have also yielded Velociraptor, Saurornithoides, Pinacosaurus and early eutherian mammals.

Long before any of this, the folklorist Adrienne Mayor has argued, travellers and traders crossing these deserts found beaked, four-legged Protoceratops skeletons guarding nests and told of griffins, the lion-bodied, eagle-beaked monsters of Greek legend.

The expeditions carried hundreds of specimens to New York, and the public stories of Gobi riches helped kick-start a black market that drained fossils out of Mongolia for decades, and recent years have brought efforts to repatriate them. It is now illegal to remove fossils from the Flaming Cliffs without the proper permits, so walk the red rock freely and leave every bone where it lies.