Discovered dinosaur embryos 66 million years ago

Scientists announced the discovery of an exquisitely preserved dinosaur embryo from at least 66 million years ago that was preparing to hatch from its egg just like a chicken.

The fossil was discovered in Ganzhou, southern China and belonged to a toothless theropod dinosaur, or oviraptorosaur, which the researchers dubbed "Baby Yingliang."

"It is one of the best dinosaur embryos ever found in history," University of Birmingham researcher Fion Waisum Ma, who co-authored a paper in the journal iScience, said.

Ma and colleagues found Baby Yingliang's head lay below its body, with the feet on either side and back curled -- a posture that was previously unseen in dinosaurs, but similar to modern birds.

In birds, the behavior is controlled by the central nervous system and called "tucking." Chicks preparing to hatch tuck their head under their right wing in order to stabilize the head while they crack the shell with their beak. 

Embryos that fail to tuck have a higher chance of death from an unsuccessful hatching.

"This indicates that such behavior in modern birds first evolved and originated among their dinosaur ancestors," said Ma.

Oviraptorosaurs, which means "egg thief lizards,"  were feathered dinosaurs that lived in what is now Asia and North America during the Late Cretaceous period. 

They had variable beak shapes and diets, and ranged in size from modern turkeys at the lower end to massive Gigantic Raptors, that were eight meters (26 feet) long.

Baby Yingliang measures around 27 centimeters (10.6 inches) long from head to tail, and lies inside a 17 centimeter-long egg at the Yingliang Stone Nature History Museum.