A fossilized adult oviraptorid theropod dinosaur has been uncovered in rocks in Ganzhou City, China. The mother dinosaur was sitting on at least 24 eggs and seven preserved bones of partial embryos. “Dinosaurs preserved on their nests are rare, and so are fossil embryos. This is the first time a non-avian dinosaur has been found sitting on a nest of eggs that preserve embryos, in a single spectacular specimen,” said Shundong Bi, one of the lead authors.

©Shundong Bi, Yunnan University

Due to the brooding posture, it is thought the dinosaur was in the process of incubating the eggs, each about 21.5 × 8.5 cm (8.5 × 2.5ʺ). The embryos were in the late stages of development, so the mother dinosaur had looked after the eggs for some time. The specimen also preserved a cluster of pebbles in her abdominal region thought to be gastroliths, or ‘stomach stones’. These were deliberately swallowed, to help the dinosaur digest its food.

The research paper gave no explanation as to how the spectacularly preserved fossil was formed. In order to preserve the dinosaur, eggs, and embryos before they could decay, these (like countless billions of other fossils) would need to have been covered rapidly by sediment. Yet this had to happen in such a way as to not disrupt the general arrangement of this maternal scene, explaining the extreme rarity of such finds.

Rather than being an alleged 70 million years old, the rocks enclosing them were formed in the Noahic Flood around 4,500 years ago. Such a global catastrophe would have transported and laid down huge amounts of sediment under many complex and differing sets of conditions.

• Bi, S. and 10 others, An oviraptorid preserved atop an embryo-bearing egg clutch sheds light on the reproductive biology of non-avialan theropod dinosaurs, Science Bulletin, 16 Dec 2020.
• Elassar, A., Researchers discover a dinosaur preserved sitting on a nest of eggs with fossilized embryos, a first, edition.cnn.com, 13 Mar 2021.