Zhengheornis

Zhengheornis is one of the smallest known early bird relatives, weighing only about as much as a modern robin (74 to 163 grams).2

Its tail had 15 short vertebrae but no pygostyle, showing that tail shortening happened before the bones fused together in bird evolution.2

The name 'buyu' means 'unexpected' in Mandarin, because scientists were surprised by its unusual tail and pelvis.1

Zhengheornis lived alongside other early birds like Fujianvenator and Baminornis in the Zhenghe Fauna of Late Jurassic China.2

Scientists think Zhengheornis was not especially good at climbing trees or walking on the ground, unlike some of its relatives.2

The only known fossil was found in 2024 and includes bones, feather traces, and parts of the arms, legs, and pelvis.1