DINOSAURS PROBABLY REPRODUCED by laying eggs. The eggs of several types of dinosaur have been found, but the best-preserved are in nests of Protoceratops and Maiasaura.
In the 1920's an expedition to the Gobi Desert in Mongolia discovered one of the most amazing collections of dinosaur skeletons ever found. At one site there were many complete skeletons of Protoceratops. The remains included young dinosaurs and which had probably just hatched, together with undisturbed nests of unhatched eggs.
These remains suggest that the mother Protoceratops would carefully scoop out a nest in the sand and then lay her eggs in a ring, with their narrow ends pointing inwards. Several nest were found in the same are, suggesting that many females used the same breeding ground. They may even have shared the same nests, taking it in turns to incubate the eggs and sharing the care of the tiny hatchlings. A large, shared nesting site would also have been safer. Oviraptors, which lived 82-69 million years ago, certainly ate the eggs of Protoceratops which lived between 83 and 76 million years ago. One fossilized Ovirator, with a badly crushed skull, has been found on top of a clutch of Protoceratops eggs, perhaps caught in the act of strealing them by an irate parent