Xianglong
Encyclopedia
Xianglong is a genus
of Cretaceous
lizard
discovered in the 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 Xianlong 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 iguania
ns 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.
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 centimetres (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.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
lizard
Lizard
Lizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...
discovered in the Liaoning Province of China
People's Republic of China
China , officially the People's Republic of China , is the most populous country in the world, with over 1.3 billion citizens. Located in East Asia, the country covers approximately 9.6 million square kilometres...
. It is known from LPM 000666, a single complete skeleton with skin impressions. The specimen comes from the Barremian
Barremian
The Barremian is an age in the geologic timescale between 130.0 ± 1.5 Ma and 125.0 ± 1.0 Ma). It is a subdivision of the Early Cretaceous epoch...
-age Lower Cretaceous Yixian Formation
Yixian Formation
The Yixian Formation is a geological formation in Jinzhou, Liaoning, People's Republic of China, that spans 11 million years during the early Cretaceous period...
, near Yizhou. The most notable feature about Xianlong is its bizarre oversized ribs, eight on each side, which were attached to a membrane of body tissue and allowed the lizard to glide
Flying and gliding animals
A number of animals have evolved aerial locomotion, either by powered flight or by gliding. Flying and gliding animals have evolved separately many times, without any single ancestor. Flight has evolved at least four times, in the insects, pterosaurs, birds, and bats. Gliding has evolved on many...
. It was an acrodont
Acrodont
Acrodont is a formation of the teeth whereby the teeth are consolidated with the summit of the alveolar ridge of the jaw without sockets. The term also refers to species of reptiles that have such a formation. This formation is common in the order Squamata, with the only other teeth formation in...
lizard, and a cladistic analysis indicates it was grouped with iguania
Iguania
Iguania is the suborder of Squamata that contains the iguanas, chameleons, agamids, and "New World lizards" such as anoles and Phrynosomatidae...
ns such as agamines
Agamidae
Agamids, lizards of the family Agamidae, include more than 300 species in Africa, Asia, Australia, and a few in Southern Europe. Many species are commonly called dragons or dragon lizards. Phylogenetically they may be sister to the Iguanidae, and have a similar appearance. Agamids usually have...
, 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 squirrelFlying squirrel
Flying squirrels, scientifically known as Pteromyini or Petauristini, are a tribe of 44 species of squirrels .- Description :...
and the Malabar Flying Frog, Rhacophorus malabaricus
Rhacophorus malabaricus
The Malabar Flying Frog is a moss frog species found in the Western Ghats of India.-Behavior:The term "flying frog" refers to its ability to break their fall by stretching the webbing between their toes when making leaps down from the treetops...
, 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
Dragon
A dragon is a legendary creature, typically with serpentine or reptilian traits, that feature in the myths of many cultures. There are two distinct cultural traditions of dragons: the European dragon, derived from European folk traditions and ultimately related to Greek and Middle Eastern...
) and Triassic
Triassic
The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...
fossil reptiles such as Kuehneosaurus
Kuehneosaurus
Kuehneosaurus is an extinct genus of Late Triassic reptile from the United Kingdom. Measuring 72 centimetres long , it had "wings" formed from ribs which jutted out from its body by as much as 14.3 cm, connected by a membrane which allowed it to slow its descent when jumping from trees...
, but the Triassic look-alikes lived over 100 million years before Xianglong. Despite the 11 centimetres (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
- http://news.nationalgeographic.com/news/2007/03/070320-gliding-lizard.html
- http://www.livescience.com/animalworld/070319_gliding_lizard.html