[Explanation] In front of us, the fossil with a history of 72 to 66 million years belongs to a toothless theropod dinosaur. It is the most complete dinosaur embryo recorded in science so far. This research was published on December 22, 2021 in " iScience" (Interdisciplinary Science) magazine.
A research team composed of scientists from institutions in China, the United Kingdom, and Canada studied a dinosaur embryo that was well preserved in egg fossils.
The fossil was discovered in the Late Cretaceous strata in Ganzhou, Jiangxi, southern China, and is currently in the collection of the Yingliang Stone Natural History Museum in Fujian Province.
On December 22, this dinosaur embryo was unveiled in Fuzhou, attracting everyone's attention.
[Concurrent] Xing Lida, Associate Professor, China University of Geosciences (Beijing)
This time we found a very rare specimen. The bones in the embryos of these dinosaurs that we have seen in the world before are scattered in all aspects. It is very rare that fossils like this kind of very well-preserved posture are very rare.
[Explanation] The reporter saw that the preserved state of this dinosaur embryo is quite primitive, without too much interference from fossilization, and clearly shows its state of survival.
The total length of the individual from head to tail is estimated to be 27 cm, curled in a long egg fossil with a length of 17 cm.
Fujian Province Yingliang Stone Natural History Museum calls this specimen "Yingliang Beibei".
[Concurrent] Niu Kecheng, Executive Director, Yingliang Stone Natural History Museum, Fujian Province
The point that we cleaned up at the beginning was actually cleaned up to its head. After we discovered that this head was actually a big surprise, because the specimens of the head of dinosaur embryos were already very scarce, and then repaired later. Afterwards, it was discovered that some of its forelimbs and hindlimbs, including the tail vertebrae such as the ribs, were very intact and curled up in the egg, so with the continuous repairs in the past six months, we are also pleasantly surprised and continue to discover these surprises.
[Explanation] Based on the short, tall, toothless skull of the specimen, "Yingliang Beibei" was identified as an egg-thief.
The research team found that the preservation posture of "Beibei Yingliang" is unique among known dinosaur embryos. Its head is under the body, its feet are on both sides, and its back is curled up along the blunt end of the egg.
This posture is similar to that of modern bird embryos, which has never been found in previous dinosaur embryo fossils.
[Concurrent] Xing Lida, Associate Professor, China University of Geosciences (Beijing)
It looks like its head is curled up in the position of its belly, and its two legs are still raised high. Then this posture is very similar to one stage of the bird's shelling, which means that the bird's shell is before the shell. This kind of curling up posture may have appeared in the age of dinosaurs, tens of millions or even hundreds of millions of years ago.
This is very important to reveal some key nodes in the evolution from dinosaurs to birds.
[Explanation] By comparing the "Yingliang Beibei" with embryos of other theropods, long-necked sauropods, and birds, the research team proposed that the contraction behavior originally thought to be unique to birds may be It first evolved from the theropod dinosaurs tens of millions or hundreds of millions of years ago.
The discovery of more embryo fossils will play an extremely important role in further testing this hypothesis.
[Concurrent] Xing Lida, Associate Professor, China University of Geosciences (Beijing)
This specimen has completed the phased research, and there are more dinosaur embryos in our collection sequence, then we will continue to do some in-depth research in the direction of this dinosaur baby, such as studying their physiology, behavior, and some ancient We gradually revealed ecological information.
Reporter Wu Shengwei reports from Fuzhou, Fujian
Editor in charge: [Tian Boqun]