Chaoyangia

Chaoyangia is an extinct genus of euornithean birds, containing the single species Chaoyangia beishanensis. This species is known from a single fossil specimen consisting of a partial skeleton including vertebra, ribs, hips, and upper legs. The specimen (museum catalog number IVPP V9934) was discovered in the Jiufotang Formation near the city of Chaoyang in Liaoning province, China. This rock formation has been dated to the Aptian age of the Early Cretaceous period, 120 million years ago.

==Description== C. beishanensis, known only from a single partial skeleton, is relatively poorly known compared to other primitive euornitheans. Chaoyangia were small, basal euornithean birds characterized by more than eight fused sacral vertebrae (those connected to the hips), uniquely long, slender, and angled uncinate processes on the ribs, and a distinct 'neck' in the upper leg bone (femur). Overall, the known skeleton is very similar to another primitive Chinese euornithean bird, Zhongjianornis, which is known from a much more complete skeleton.