Discover a rare little dinosaur stuck in its fossilized egg

deviant position

The precious egg was “rediscovered” in 2015, when the staff of yingliang He was rearranging the company’s fossil record with plans to open a natural history museum. The egg is a little longer than an ostrich egg, and more flattened, and at that point it was noticed that the surface was broken, and the small bones were shown inside.

“At that moment we realized there could be a fetus inside,” says study author Waisum Ma, a PhD researcher at the University of Birmingham in the UK.

A technician removed one side of the shell and part of the sediment that filled the egg, “freezing” the baby dinosaur over time in the immediate pre-birth stage. Realizing the importance of discovery, yingliang I contacted the study’s lead author, Lida Xing of Beijing University of Geosciences, who began assembling a team to study the perfectly preserved specimen.

While many dinosaur eggs have been found over time, embryos are rare, and even well-preserved embryos. Matthew Lamana, a paleontologist at Carnegie Museum of Natural History Pittsburgh, who was not part of the study team.

So far, only two semi-formed oviraptorosaurus embryos have been found, says Ma. “Wonderful,” he recalls thinking when he first saw the pictures of the fetus, “It’s the best dinosaur fetus I’ve ever seen. I’ve never seen it.” In fact, only a few parts of the skeleton appear to be missing, Ma continues, including the front leg and part of the tail.

For other fossils, the scientists used CT scans to reveal details of the bones in the eggs. However, the type of sediment deposited inside the egg made it difficult for scientists to distinguish the bones from the rest. However, the team was able to study the fossil’s exposed surface in detail, comparing it to two other aphiraptorosaur embryos found earlier.

head yingliang baby Found folded on the abdomen, the hind legs bent with the knees in correspondence to the articulation of the front legs; The back follows the curvature of the shell end, where the bladder may be a small hiatus. These are all characteristics similar to those of current chick embryos, which as they get older curl up more and more until their head is placed under the right wing. This sequence of positions (in English it is called tuck, literally “folding”) is necessary for successful hatching.

the yingliang baby She wasn’t in final position right before birth, but “she was getting there,” Zelenitsky says. The two slightly different positions of oviraptorosaurus embryos could indicate a series of positions that follow development, similar to those of our chicks. The team speculates that the sequence of the file tuck From birds it can be traced back to oviraptorosaurs millions of years ago.