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...