Discovered dinosaur egg: the embryo is perfectly preserved

Found in China the perfectly preserved embryo of an oviraptorosaurus: reveals an important connection with modern birds

It had been in the warehouse of a museum, forgotten for years among other fossils. However, the dinosaur egg hidden in the rooms of the Yingliang Stone Natural History Museum in Nan'an, China, showed small bone marks on the surface that intrigued a museum worker.

A 70-million-year-old embryo

The bone marks poking out of the dinosaur egg's shell could indicate the presence of an embryo inside an egg that never hatched. So the Museum wisely decided to contact the University of Birmingham, to study what looked like a potentially very important specimen for the scientific community.

What was discovered inside the dinosaur egg found in the museum's warehouse, however, exceeds all possible expectations: inside is the embryo of an oviraptorosaur, as suspected by the museum worker who noticed it in 2015.

But there's more: the embryo, which is about 70 million years old, is in perfect condition. Waisum Ma of the University of Birmingham took part in the study of the egg sent from southern China, and admits that no one expected to find such a beautifully preserved embryo inside.

The unborn dinosaur looks like a small skeleton 24 centimeters long, curled in on itself and with its head tucked firmly to the rest of its body, while the egg is 17 centimeters long by 8 centimeters wide.

Dating places the exceptional fossil between 66 and 72 million years ago: probably, the researchers speculate, it was quickly covered by a blanket of sand or mud that has protected it to this day.

Dinosaurs and birds

The position of the embryo, which is exceptionally clear thanks to the fossil's state of perfect preservation, sheds new light on an issue that is well known among paleontologists and dinosaur enthusiasts.

Birds, as we know them today, are said to be nothing more than dinosaurs. The most recent confirmations on the subject go from the discovery that some dinosaurs had feathers to the curious hypothesis that birds have never really "lost" their teeth on the way of evolution, keeping them perhaps in the form of a genetic trait not expressed.

From the embryo of oviraptorosaurus found in China comes a new important information on the relationship between dinosaurs and birds: the position of the small dinosaur, in fact, is almost identical to that adopted by the chicks preparing for hatching.

What is a trait that has always been associated with modern birds, therefore, actually seems to have evolved much earlier in dinosaurs: "we have never had such well-preserved embryos available to observe these things so well, before today," says Ma.

The study, just published in the journal iScience, clearly speaks of "avian pre-hatching positions", and is probably only the first of the important studies that will be possible thanks to the small oviraptorosaur embryo discovered almost by accident in a warehouse.