Incisivosaurus

Taxobox
name = "Incisivosaurus"
fossil_range = Early Cretaceous


image_width = 200px
image_caption = Restoration of "Incisivosaurus" by Portia Sloanrfu-c|2007-09-06
regnum = Animalia
phylum = Chordata
classis = Sauropsida
superordo = Dinosauria
ordo = Saurischia
subordo = Theropoda
infraordo = Oviraptorosauria
genus = "Incisivosaurus"
species = "I. gauthieri"
binomial = "Incisivosaurus gauthieri"
binomial_authority = Xu "et al.", 2002

"Incisivosaurus" ("incisor lizard") is a genus of small, probably herbivorous theropod dinosaur from the early Cretaceous Period of what is now the People's Republic of China. The first specimen to be described (by Xu "et al." in 2002) was collected from the lowermost levels (fluvial beds) of the Yixian Formation (dating to the Barremian stage about 130 million years ago) in the Sihetun area, near Beipiao City, in western Liaoning Province. The most significant, and highly unusual, characteristic of this dinosaur is its apparent adaptation to an herbivorous or omnivorous lifestyle. It was named for its prominent, rodent-like front teeth, which show wear patterns commonly found in plant-eating dinosaurs. The species name honors Dr. Jacques Gauthier, a pioneer of the phylogenetic method of classification.Xu, X., Cheng, Y.-N. Wang, X.-L., and Chang, C.-H. (2002). "An unusual oviraptorosaurian dinosaur from China." "Nature", 419: 291-293.]

Description

The initial description of "Incisivosaurus" by Xu "et al." showed that the skull, which measures approximately 10 cm in length (4 inches), preserves the most complete dentition known for any oviraptorosaurian. Their cladistic analysis indicated that "Incisivosaurus" lies at the base of the oviraptorosaurian group, making it more primitive than "Caudipteryx" and the oviraptorids. A subsequent study by Osmolska "et al." in 2004 described the distinguishing skeletal features of "Incisivosaurus", including a long snout that made up about half the total length of the skull, a slender lower jaw with a long fenestra (opening), and its distinctive, large, flattened front teeth. In addition to these unique features, "Incisivosaurus" shared many traits with more typical oviraptorosaurs, allowing its classification with that group. Several features, including its numerous teeth (most advanced oviraptorids were toothless), show that it was a primitive member of the group, and several features of the skull even support a relationship with the therizinosaurs, another theropod group that was probably herbivorous.Osmolska, H., Currie, P. J., and Barsbold, R. (2004). "Oviraptorosaura." in "The Dinosauria" (2nd edition), Weishampel, D. B., Dodson, P., and Osmólska, H., (eds). University of California Press.]

"Incisivosaurus" is assumed to have been feathered like most other maniraptoran theropods and may have been secondarily flightless. Its total body length has been estimated at just under 1 meter (3 ft.). It is possible that "Incisivosaurus" is the same species as "Protarchaeopteryx", though more fossil specimens are needed before the two can be directly compared.

Possible uses of teeth

The teeth might have used to strip flesh off of bone.Fact|date=June 2008

In popular culture

"Incisivosaurus" was featured in the third episode of the ITV series "Prehistoric Park", which theorized that "Incisivosaurus" used its "wing" feathers for displaying and that it or a similar form was ancestral to gliding and flying forms.

References

External links

* [http://www.dinodata.org/index.php?option=com_content&task=view&id=6695&Itemid=67 "Incisivosaurus"] at DinoData
*sinopix.com [http://sinopix.com/sinopixweb/photo_pop.jsp?photo_id=9587] (photo of skull, with skull of juvenile "Liaoceratops" below)