A rare dinosaur embryo was found perfectly preserved in the egg and fossilized in a position that until now was thought to be typical only of birds about to be born. The specimen was renamed ‘Baby Yingliang’ and dates back to at least 66 million years ago.
It was found in southern China, in Ganzhou, and its identikit was published in the magazine iScience by an international team led by the University of Birmingham and the Chinese University of Geosciences in Beijing. It is an oviraptosaurus, a ‘relative’ of birds, which was preparing to hatch from its egg just like a chick. “Most of the dinosaur embryos are incomplete with the disjointed skeletons: we were very surprised to see this embryo perfectly preserved in its egg, in a posture similar to that of birds. It is something that has never been seen so far in non-dinosaurs. aviani “, comments Waisum Ma of the University of Birmingham. Baby Yingliang is 27cm long from head to tail and sits inside a 17cm egg. Its head is folded under the belly, flanked by the legs, while the back follows the curvature of the shell. “It looks like a small bird curled up in its egg, further proof that many features of modern birds first evolved in their ancestors dinosaurs,” explains Steve Brusatte of the University of Edinburgh.
The “turn-up”: Baby Yingliang like birds
Oviraptorosaurs, literally the “egg-stealing” dinosaurs, were feathered dinosaurs that lived in what is now Asia and North America during the Late Cretaceous. They had different beak shapes and varying diets. Their size ranged from that of modern turkeys to large Gigantoraptors, over eight meters long. Baby Yingliang would have grown two to three meters if he had lived to be an adult and probably would have fed on plants. The position of Baby Yingliang in the egg is assumed by today’s birds and is called “tucking”. Chicks preparing to hatch put their heads under the right wing to stabilize it while breaking the shell with their beak. “This indicates that such behavior in modern birds evolved and originated in their dinosaur ancestors,” said Ma.
The fossil, recovered in Jiangxi province near Ganzhou city, was acquired in 2000 by the director of a company called Yingliang Group, but then ended up in a warehouse where it was recovered only a decade ago by the staff of Yingliang Stone. Nature History Museum in Xiamen, where it is still preserved today. The research team suspected the fossils might contain unborn dinosaurs and scraped off part of Baby Yingliang’s eggshell to discover the embryo hidden inside. Researchers think the creature is between 72 and 66 million years old and likely preserved from a sudden mudslide that buried the egg, protecting it from scavengers. The team hopes to study Baby Yingliang in more detail using advanced scanning techniques to visualize the entire skeleton, including the skull bones, because part of the body is still covered in rock.