66 Million Years Old Fossilized Egg Guards Rare Dinosaur Embryo

Published on 12/22/2021 06:00

(Credit: Lida Xing / Disclosure)

Over the past 100 years, archaeologists have discovered many fossilized dinosaur eggs and nests. But these scientists were searching for a rare artifact: a well-preserved embryo. The tiny hoard – a bird-like embryo from 72 to 66 million years old – was found among a series of prehistoric objects taken from Ganzhou city in southern China’s Jiangxi province. Details of the discovery are in the latest issue of iScience.

“Most known non-avian dinosaur embryos are incomplete or have loose skeletons. We were surprised to find this embryo in such a good condition,” says Wisom Ma, a researcher at the University of Birmingham, UK, and one of the study’s authors.

The egg that Ma and other scholars evaluated was part of a collection of artifacts acquired by the Yingliang Group in 2000. The collection was forgotten for years, until a team from the Yingliang Stone Natural History Museum, who received the materials as a donation, decided to classify all the items.

The fetus, called Baby Yingliang, belonged to oviraptorosaurs, a terrestrial type of dinosaur. Experts also found that the fetus was in a different position than other flightless species, in a position hitherto considered unique to birds. “We have observed a position of the head closer to the body, with the feet on each side, in a position that had hitherto not been recognized in a non-avian dinosaur. This raises the possibility that bending (pillar) behavior may have evolved first among non-avian theropods during the Cretaceous period”, Rating the authors of the article.

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Birds have been known to develop a series of netting poses, bending their bodies and placing their heads under their wings, just before they hatch. By comparing ‘Baby Yingliang’ with embryos of other theropods, long-necked dinosaurs and sauropods, the team suggested that folding behavior, once considered unique to birds, first evolved in theropods tens or hundreds of millions of years ago. Ago.

However, more studies are needed. The British team stresses that the data needs to be better evaluated, if possible, compared to analyzes made on other fossils from the same period. They also say they plan to use advanced imaging techniques to get more details about the fetus’s internal anatomy, such as the bones of the skull and other parts of the body still covered in rocks.