Fossil discovery in China reveals ancient flightless bird species

Researchers have identified a 150-million-year-old bird fossil in China that challenges existing theories on avian evolution. The newly discovered species, Yuezhuornis yangyuanensis, lived during the Late Jurassic period and represents the earliest known example of a bird lineage losing its ability to fly.

Discovered in the Zhenghe Fauna of Fujian Province, the crow-sized creature exhibits a mix of avian and dinosaur characteristics. It possessed serrated teeth similar to those of meat-eating deinonychosaurs and a specialized second toe with a curved, sickle-shaped claw. These findings suggest that early bird evolution was not a linear progression toward improved flight, but rather a complex adaptation to diverse environments, including ground-based lifestyles.