72-million-year-old egg reveals new link between dinosaurs and birds

Story by CBC Kids News • 2022-01-13 06:00

Unhatched dino nicknamed Baby Yingliang


Move over Baby Yoda, it’s Baby Yingliang’s time to shine.

The unhatched dino was discovered — still inside its egg — in Ganzhou, southern China, about 20 years ago, but was only recently investigated by scientists for the first time.

Nicknamed Baby Yingliang, it is one of the most well-preserved dinosaur embryos ever found.

Researchers from Canada, China, Scotland and England studied the fossil and published their findings in a scientific journal called iScience on Dec. 21.

While there was lots to learn from The Mandalorian’s Baby Yoda when it first appeared in the Disney+ series, Baby Yingliang’s contribution carries a bit more force.

Scientific force, that is, not Star Wars force.

How? The discovery sheds new light on the connection between dinosaurs and birds by showing that they may have had similar ways of breaking out of their shells.

Perfectly preserved

The fossilized skeleton belonged to a baby dinosaur from 72 million years ago.

The dinosaur embryo is from a type of dinosaur called a theropod. They had hollow bones and three-toed limbs. The Tyrannosaurus rex was also a theropod. (Image credit: Lida Xing)

The dinosaur, called an oviraptorosaur, was found still inside its egg in a rock layer from the late Cretaceous era.

The specimen is 27 centimetres in length from its head to its tail, which is roughly the size of a standard ruler or two litre pop bottle.

The best part about it? Scientists say the fossil is really well preserved.

“I couldn't believe my eyes,” University of Calgary paleontologist Darla Zelenitsky said.

“I'd never seen anything like it. It's truly spectacular.”

That's because these skeletons are so fragile and tend to fall apart.

“The chances of finding a dinosaur embryo like this, curled in a life position [is very rare],” she added. “It's complete from the tip of the snout all the way to the end of the tail.”

What Baby Yingliang is teaching us

Until now, scientists didn’t really know how dinosaurs developed inside their shells.

The newly discovered embryo reveals some new details about this process.

The orange and pink object shows what the dinosaur embryo may have looked like before being fossilized. (Image credit: Wang Yi) 

According to the scientists, the dinosaur’s posture, with its head tucked and its spine bent along the egg’s narrow top, is similar to the posture birds take right before they hatch.

That position is connected to a behaviour called “tucking,” which is crucial in allowing birds to hatch successfully.

Until now, tucking was thought to be unique to birds.

“It is interesting to see this dinosaur embryo and a chicken embryo pose in a similar way inside the egg, which possibly indicates similar prehatching behaviours,” said Fion Waisum Ma, joint main author of the study and PhD researcher at England’s University of Birmingham, in a news release from the University of Calgary.

Now, scientists believe that the tucking behaviour was likely passed down to birds through their dinosaur ancestors.

They say there is still a lot to learn about how dinosaurs developed in their shells, but more rare discoveries like Baby Yingliang are needed to paint a clearer picture.

Have more questions? We'll do our best to look into it for you. Ask for permission from your parent or guardian and email us at cbckidsnews@cbc.ca.

With files from The Canadian Press

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