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

Chinese scientists have discovered the fossil of Yuezhuornis yangyuanensis, the earliest known flightless bird. This 150-million-year-old Late Jurassic avialan was found in China. The discovery provides evidence that not all early birds evolved the ability to fly. This finding may challenge existing assumptions, including those of Charles Darwin, which suggested that flightlessness in birds was a secondary adaptation that occurred after flight had been mastered. The fossil indicates that some early bird lineages may have evolved without ever developing flight.