Dhaka, Oct. 15 -- A 150-million-year-old fossil unearthed in southeastern China is rewriting what scientists thought they knew about the earliest birds -- and it turns out one of them may have preferred running to flying.

The newly identified species, named Yuezhuornis yangyuanensis, dates to the Jurassic Period and ranks among the oldest-known birds alongside Europe's celebrated Archaeopteryx.

But unlike its contemporaries, Yuezhuornis appears to have already scaled back its flying ability in favour of ground movement -- more roadrunner than sparrow, The Independent reported.

Its wings, while fully formed, were roughly a third shorter than its legs -- far too small for sustained flight. Comparisons with 377 living bird species found i...