A Theropod Dinosaur Embryo and the Affinities of the Flaming Cliffs Dinosaur Eggs

• DOI: 10.1126/science.266.5186.779
• Publication Date: 2006-10-06T00:01:25Z
• Authors: Mark A. Norell; James M. Clark; Dashzeveg Dembere...; Barsbold Rhinchen; Luis M. Chiappe; Amy R. Davidson; Malcolm C. McKenna; Perle Altangerel; Michael J. Novacek
• Keywords: 01 natural sciences; 0105 earth and related environmental sciences

An embryonic skeleton of a nonavian theropod dinosaur was found preserved in an egg from Upper Cretaceous rocks in the Gobi Desert of Mongolia. Cranial features identify the embryo as a member of Oviraptoridae. Two embryo-sized skulls of dromaeosaurids, similar to that of Velociraptor , were also recovered in the nest. The eggshell microstructure is similar to that of ratite birds and is of a type common in the Djadokhta Formation at the Flaming Cliffs (Bayn Dzak). Discovery of a nest of such eggs at the Flaming Cliffs in 1923, beneath the Oviraptor philoceratops holotype, suggests that this dinosaur may have been a brooding adult.