Perfectly preserved embryo linking birds and dinosaurs discovered in China

New Delhi: A team of researchers has discovered a 72 to 66 million year old embryo preserved in a fossilized dinosaur egg. Scientists from the University of Birmingham and the University of Geosciences of China (Beijing) have published their study on the embryo in the journal “iScience”.

According to the study, the embryo belongs to a toothless theropod dinosaur or an oviraptorosaur. Dubbed “Baby Yingliang,” the embryo was discovered in the Late Cretaceous rocks of Ganzhou in southern China.

The fossil is one of the most complete dinosaur embryos ever found. This suggests that these dinosaurs developed bird-like postures close to hatching.

The discovery sheds light on the link between the behavior of modern birds and dinosaurs, according to the study.

Baby Yingliang is unique

“Baby Yingliang’s” posture was unique among known dinosaur embryos, according to the study. Indeed, in the embryo, the head is under the body, the feet are on each side and the back is rolled up along the blunt end of the egg. The posture matches that of modern bird embryos and was previously unrecognized in dinosaurs.

Tucking, which is a behavior found in modern birds, is controlled by the central nervous system and is critical to hatching success. According to the study, the posture observed in the fossilized embryo shows similarities to the folded behavior.

This suggests that such pre-hatch behavior may originate from non-avian theropods.

The fossilization did not disturb the embryo, which was maintained in its life position. The embryo is estimated to be 27 centimeters long from head to tail and lies inside an elongated egg 17 centimeters long. The unique fossil was sent to the Yingliang Stone Nature History Museum.

Fion Waisum Ma, the study’s co-first author, said dinosaur embryos are among the rarest fossils and most of them are incomplete with dislocated bones, according to a University statement. from Birmingham. He added that the researchers were very excited about the discovery of “Baby Yingliang” as it is preserved in very good condition. Also, it helps scientists get answers to many questions about dinosaur growth and reproduction, he explained.

He said it was interesting to see the dinosaur embryo and a chicken embryo laying the same way inside the egg, possibly indicating similar behaviors before hatching.

Baby Yingliang has a deep, toothless skull

Based on its deep, toothless skull, “Baby Yingliang” was identified as an oviraptorosaur, according to the study. Oviraptorosaurs have been known since the Cretaceous period in Asia and North America and are feathered theropod dinosaurs, characterized by their varying beak shapes and body sizes.

When modern birds exhibit fallback behavior, they bend their bodies and put their heads under their wing, shortly before hatching.
The researchers proposed that the tucking behavior, which was thought to be unique to birds, first evolved in theropod dinosaurs tens or hundreds of millions of years ago.

Harry D. Gonzalez