Dinosaur embryo study backs ancestral link to birds

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Dinosaur embryo study backs ancestral link to birds(图1)
The "Baby Yingliang" dinosaur egg fossil at Yingliang Stone Nature History Museum in Fuzhou, Fujian province. 

A new study examining an embryo from a fossilized dinosaur egg has provided further evidence supporting the notion that modern birds evolved from dinosaurs.

The embryo fossil was discovered in rocks in Ganzhou, Jiangxi province, around the year 2000 and is housed in the Yingliang Stone Nature History Museum in Fujian province, where it was dubbed "Baby Yingliang".

Estimated to be 27 centimeters from head to tail, the creature lies inside a 17-cm-long egg. Paleontologists believe it belongs to a toothless theropod dinosaur, or oviraptorosaur, dating back 72 to 66 million years, within the Cretaceous Period.

The posture of the embryo within the egg implies that these dinosaurs developed birdlike postures close to hatching, according to the study published in the journal iScience on Wednesday.

Scientists from China, Britain and Canada who worked on the study found the posture of "Baby Yingliang" unique among known dinosaur embryos-its head lies below the body, with the feet on either side and the back curled along the blunt end of the egg. Previously unrecognized in dinosaurs, this posture is similar to that of modern bird embryos.

Before hatching, birds are known to develop a series of tucking postures, bending their body and extending their head under their wings. Embryos that fail to attain such postures have a higher chance of death due to unsuccessful hatching.

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