Perfectly preserved dinosaur embryo found that is at least 66 million years old.

A 72 to 66 Million year old embryo found inside a fossilized dinosaur egg sheds.

New light on the link between the behavior of modern birds and dinosaurs. 

According to a new study the embryo dubbed baby 'Yang' was discovered in the late Cretaceous rocks of Gonzo, Southern China. And belongs to a toothless theropod dinosaur or over pterosaur among the most complete dinosaur embryos ever found. 

The fossil suggests that these dinosaurs developed bird-like postures close to hatching.

Scientists found the posture of baby unique among known dinosaur embryos. It's head lies below the body with the feet on either side and the back curled along the blunt end of the egg.

Previously unrecognized in dinosaurs this posture is similar to that of modern bird embryos.

In modern birds such postures are related to tucking a behavior controlled by the central nervous system and critical for hatching. Success after studying egg and embryo, researchers believe that such pre-hatching behavior previously considered unique to birds may have originated among non-avian theropods led by scientists from the university of Birmingham and China university of Geosciences Beijing. 

The research team from institutions in China, UK and Canada published its findings.

The embryo is articulated in its life position without much disruption from fossilization estimated to be 27 centimeters long from head to tail. 

The creature lies inside a 17 CM long along the toilet egg. 

Dinosaur embryos are some of the rarest fossils and most of them are incomplete with the bones dislocated.

Baby Yang is preserved in a great condition and helps us answer a lot of questions about dinosaur growth and reproduction with it. 

It is interesting to see this dinosaur embryo and a chicken embryo pose in a similar way inside the egg, Which possibly indicates similar pre-hatching behaviors.

Baby Yang was identified as an overlapped pterosaur based on its deep toothless skull.

Overlapped pterosaurs are a group of feathered theropod dinosaurs, Closely related to modern day birds known from the Cretaceous of Asia and North America.

Their variable big shapes and body sizes are likely to have allowed them to adopt a wide range of diets including herbivory, omnivore and carnivory. Birds are known to develop a series of tucking postures in which they bend their body and bring their head under their wing. Soon before hatching embryos that fail to attain such postures have a higher chance of death.

Due to unsuccessful hatching by comparing baby Yang with the embryos of other theropods long-necked sauropod dinosaurs and birds, The team proposed that tucking behavior which was considered unique to birds first evolved in theropod dinosaurs many tens or hundreds of million.