Xianglong

This article is about the extinct Cretaceous lizard. For other uses, see Xianglong (disambiguation).

Xianglong Temporal range: Early Cretaceous
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Pencil drawing of Xianglong zhaoi
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Sauropsida
Order:	Squamata
Suborder:	Iguania
Genus:	Xianglong Li et al., 2007
Species
X. zhaoi Li et al., 2007 (type)

Xianglong (meaning "flying dragon" in Chinese) is a genus of Cretaceous lizard discovered in the Zhuanchengzi, near Yizhou, Yixian, Liaoning Province of China. 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.

The fossil specimen found was 15.5 centimetres (6.1 in) long, 9.5 centimetres (3.7 in) of which was tail, but the describers say it was 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.

Gliding ability

Xianglong is one of the few creatures that glide using their ribs. Other creatures, such as the flying squirrel and the Malabar Flying Frog, Rhacophorus malabaricus, have a different membrane attachment, toes to toes or limb to limb. Two creatures use the same way to glide, the present day Flying Lizard (genus Draco, Latin for dragon) and Triassic fossil reptiles such as Kuehneosaurus, but the Triassic look-alikes lived over 100 million years before Xianglong. Despite the 11-centimetre (4.3 in) "rib-span", the lizard might have been quite agile in the air, possibly to escape the feathered dinosaurs that coexisted with it.

Xianglong had slightly curved claws, indicating that it was arboreal. Of course, it needed to be in order to get in its "gliding mode".

Xu Xing, a Chinese paleontologist and one of the describers of Xianglong, states that it is possible Xianlong could have glided as much as half a football field, much farther than that of the modern Draco.

External links

• Photo in the News: Ancient Lizard Glided Using Its Ribs Aalok Mehta National Geographic Society March 20, 2007
• Ancient Lizard Glided on Stretched Ribs by Ker Than, LiveScience March 19, 2007 01:00pm ET
• Xianglong at the Encyclopedia of Life