In the land before our time, many dinosaurs laid eggs. Parents protect their claws, and little dinosaur babies could eventually hatch from brooding embryos. However, this process is only occasionally recorded in the fossil record. Dinosaur fossils that nest on eggs and fossils of complete egg embryos are extremely rare. But according to a 2021 article in iScience, a fully articulated dinosaur embryo was found inside a fossilised egg in a Chinese museum. The fossilised egg was found in the collection of the Eryoseki Natural History Museum and was obtained around 2000. Subsequent investigation of the collection identified what the egg was. Further investigation revealed a surprisingly complete and remarkably well-preserved dinosaur embryo inside. This specimen is between 66 and 72 million years old.
"This dinosaur embryo in its egg is one of the most beautiful fossils I have ever seen," said one of the study's authors, Professor Steve Brusatte, in a statement. This tiny prenatal dinosaur looks like a chick curled up in an egg, providing further evidence that many of the features characteristic of modern birds first evolved in the ancestors of dinosaurs. ”