Which came first?

Look: Dinosaur embryo appears freakishly like a chicken in an egg

Lida Xing

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Dinosaurs are thought to be the ancestors of today’s birds.

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These similarities may have started before they even hatched.

A newly-described fossil egg reveals an uncanny resemblance to unhatched chickens.

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Lida Xing

Lida Xing

Identified as an Oviraptorsaur, a group of dinosaurs known for their coats of feathers and hollow, toothless skulls, it looks surprisingly familiar.

Lida Xing

Such excellently preserved, unhatched dinosaur fossils are extremely rare, the researchers say.

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Baby Yingliang’s remains, which date to the Late Cretaceous period up to 72 million years ago, could reveal new details of early development in dinosaurs — and today’s chickens.

The dinosaur is curled up like how chicken embryos position themselves to prepare for hatching.

iScience

“This little prenatal dinosaur looks just like a baby bird curled in its egg, which is yet more evidence that many features characteristic of today’s birds first evolved in their dinosaur ancestors.”

Stephen Brusatte, study co-author

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The researchers looked at other types of dinosaur eggs, such as those of sauropods and other theropods, but this behavior appears unique to Oviraptosaurs — so far.

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More fossil evidence is needed to establish when dinosaurs started tucking — and how widespread it was across species. But Baby Yingliang reveals a previously unknown commonality with its modern descendants.