A fossilized dinosaur egg boasting the remains of a nearly intact embryo was discovered in southern China in 2010, then forgotten on a storeroom shelf until years later.

Now, new details are emerging about the specimen in iScience, with research lauding the discovery of the “exquisitely preserved in ovo therapod dinosaur embryo,” curled up in an egg seemingly on the cusp of hatching.

In ovo is Latin for in the egg.

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“The new embryo is a keystone fossil that reveals postural differences among the known embryonic oviraptorids curled in ovo,the iScience research explains.  

The 7-inch long and 3-inch wide egg contains the most well preserved dinosaur embryo ever discovered and provides crucial information on the link between dinosaurs and modern-day birds.

“This articulated specimen is one of the most complete non-avian dinosaur embryos yet discovered, permitting detailed anatomical study and an unprecedented glimpse at the osteology of an in-ovo bird-like, but non-avian, theropod dinosaur,” the paper said.

The embryo itself, dubbed Baby Yingliang, is nearly 9.5 inches long. It has been identified as an Oviraptorosaur, a feathered dinosaur from the Cretaceous Period found in China and North America.

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Researchers say the posture of the embryo is similar to that of a late-stage modern bird embryo, leading them to believe that possibly, “avian tucking” behavior could have originated among non-avian therapods.

Tucking is a behavior controlled by the central nervous system and critical for hatching success, the paper said, and was previously considered unique to birds.

The 70 million-year-old egg was first discovered in 2010 in China, but forgotten on a shelf inside a museum storeroom for years.

The scientists hope publication of the paper will serve as a springboard for additional research made more challenging, however, by the scarcity of the availability of in ovo images and scans.

They say that  future research on the prehatching behavior of non-avian dinosaurs will benefit from discoveries of additional embryo fossils that will provide a more precise determination of developmental stages.

For now, they are relishing in the information gained from studying Baby Yingliang.

“Dinosaur embryos are some of the rarest fossils and most of them are incomplete with the bones dislocated. We are very excited about the discovery of ‘Baby Yingliang,’” said Fion Waisum Ma, joint first author and researcher at the University of Birmingham in a statement on the university’s website. “It is preserved in a great condition and helps us answer a lot of questions about dinosaur growth and reproduction with it.”

The research was led by scientists from the University of Birmingham and China University of Geosciences (Beijing), and made up of teams from institutions in China, the United Kingdom and Canada.