Million-Year-Old Embryo Shows How Much This Dino Resembled Birds

Dec 22, 2021

The link between dinosaurs and birds has become even more clear! A rare, well-preserved embryo found inside a fossilized egg reveals striking similarities between dinosaurs and the birds they would evolve into, researchers say. The egg dates back more than 66 million years.   

In a study published in the journal iScience, the authors reported that they discovered the embryo curled up with its head between its legs. Scientists used to think that position was unique to birds. The egg is 7 inches long and oval shaped. 

The fossil also revealed a head and beak similar to that of a newly hatched bird. But the dino had tiny arms and claws rather than wings and could not fly.    

One of the study's authors called the fossil “one of the best-preserved dinosaur embryos ever found.” The egg arrived at a nature museum in China in 2000 along with a large number of fossils. It took another 15 years for staff to realize what lay inside the egg. Scientists detected bones that had fossilized after the egg cracked. Careful analysis revealed the complete fossil curled up in its shell.            

Discoveries of embryonic dinosaur fossils are very rare. They have been found at only about a half-dozen sites.     

Photo from iScience.

According to information in the second paragraph, the discovery of the fossilized dinosaur embryo is most important because of its _______.
tiny arms and claws
positioning in the egg
location and age
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