Sorry, Darwin: Chinese fossil shows that not all early birds evolved to fly

Chinese scientists have unearthed a fossil of the earliest known flightless bird, offering compelling evidence that not all early birds evolved to take to the skies.

The discovery could also challenge long-held assumptions – including ideas dating back to evolutionary theorist Charles Darwin – that flightlessness in birds arose only as a secondary adaptation after earlier species had mastered flight.

The 150 million-year-old fossil of the Late Jurassic avialan Yuezhuornis yangyuanensis found in China’s southeastern Fujian province suggests that early bird adaptation branched out into more diverse, terrestrial non-flying niches much earlier than previously thought.

“Selection for powered flight has been viewed as the main driver of early avialan skeletal modifications,” the researchers said in a paper published in the peer-reviewed journal Nature on October 14.