Xianglong

Xianglong (meaning "flying dragon" in Chinese) is a genus of Cretaceous lizard discovered in the Zhuanchengzi, near Yizhou, Yixian, Liaoning Province of China.[1]  It is known from LPM 000666, a single complete skeleton with skin impressions. The specimen comes from the Barremian-age Lower Cretaceous Yixian Formation, near Yizhou. The most notable feature about Xianglong is its bizarre oversized ribs, eight on each side, which were attached to a membrane of body tissue and allowed the lizard to glide. It was an acrodont lizard, and a cladistic analysis indicates it was grouped with iguanians such as agamines, chamaeleonids, and leiolepidines.[2]

The fossil specimen found was 15.5 centimetres (6.1 in) long, 9.5 centimetres (3.7 in) of which was tail, although the describers say it was probably a juvenile. So far this is the only known fossil gliding lizard, though there are other unrelated animals that also use their ribs to glide.[2]