(CNN) Baby pterosaurs were overachievers from birth.

A paper published Wednesday in Proceedings of the Royal Society B argues that the prehistoric reptiles could fly immediately after birth -- something that the researchers say no other vertebrates, living or extinct, have been able to do.

Before, scientists thought that pterosaurs could only fly once they had grown to nearly full size, like birds or bats. But that theory was based on fossilized embryos found in China that had poorly developed wings, according to a press release about the research

For this study, David Unwin, a paleobiologist at the University of Leicester, and Charles Deeming, a zoologist at the University of Lincoln, gathered evidence from 19 pterosaur embryos across four different species.

The two scientists compared the pterosaur embryos to data on prenatal growth in crocodiles and birds and discovered that the embryos had a long way to go before they were ready to be hatched.

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