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

TLDR

Eggshell microstructure resembles that of ratite birds and is typical of the Djadokhta Formation at the Flaming Cliffs. An embryonic skeleton of a nonavian theropod, identified as Oviraptoridae, was found in an egg from the Gobi Desert, along with two dromaeosaurid skulls, indicating that the nest at the Flaming Cliffs may have been brooded by an adult Oviraptor.

Abstract

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.