A new discovery in southern China begs the understanding of evolutionary link between birds and dinosaurs. The fossilized remains of around 72-million-year-old dinosaur embryo, which is nicknamed Baby Yingliang, gives a glimpse into the origins of bird-like behaviors – which is thought to be unique to modern species. This fossil, which is found in a well-preserved egg, represents one of the most intact dinosaur embryos ever uncovered. It allows paleontologists to see into the deep past of avian evolution.
Baby Yingliang’s story begins in the quiet storage rooms of the Yingliang Stone Natural History Museum at Nan’an in China, and not in the bustling world of paleontology. About 17 centimeters in length, the egg had sat untouched for years after being donated to the museum in 2000.
When museum staff noticed an unusual crack in the shell in 2015, the significance of the egg became clear. They discovered fossilised remains of an oviraptorosaur – a feathered dinosaur closely related to modern birds.
The way it was preserved made the embryo extraordinary in addition to its rarity and fossil age. Scientists, for the first time, were able to study a non-avian dinosaur embryo – which had adopted the “tucking” posture. This is the same behavior modern bird embryos exhibit before hatching.
This discovery challenges assumptions about the origins of bird-like behaviors and sheds new light on the evolutionary journey from dinosaurs to birds.
Curled tightly with its head tucked beneath its body and feet positioned on either side, the position of the embryo inside the egg resembles the “tucking” behavior seen in modern birds as they prepare for birth.
Controlled by the central nervous system, tucking is essential for the successful hatching of bird embryos. This behavior, for decades, was thought to be a hallmark of birds. But baby Yingliang reveals that dinosaurs may have already been displaying this behavior long before birds evolved.
