Xixiasaurus is a genus of troodontid dinosaur that lived during the Late Cretaceous Period in what is now China. The only known specimen was discovered in Xixia County, Henan Province, in central China. It would have been bird-like and lightly built, with grasping hands and an enlarged sickle-shaped claw on the second toe. It was distinct among Troodontids in having 22 teeth in each maxilla.
About Xixiasaurus in brief
Xixiasaurus is a genus of troodontid dinosaur that lived during the Late Cretaceous Period in what is now China. The only known specimen was discovered in Xixia County, Henan Province, in central China. It is estimated to have been 1. 5 metres long and to have weighed 8 kilograms. It would have been bird-like and lightly built, with grasping hands and an enlarged sickle-shaped claw on the second toe. It was distinct among Troodontids in having 22 teeth in each maxilla. The precise relationships of Xixiasosaurus with other troodonids are uncertain, but it had some similarities with Byronosaurus. The lack of serrated teeth indicates these were herbivorous, as they had lost the ability to slice meat. There has been debate about their diet, with some researchers arguing they were carnivorous, and others that they were omnivorous or herbivory. The holotype specimen consists of an almost complete skull, part of the lower jaw, and teeth, as well as a partial right forelimb. In 2010, the specimen was described as the new genus and species Xxiasaurus henanensis by the palaeontologist Lü Junchang and colleagues. The generic name refers to XIXia County coupled with saurus, meaning ‘lizard’. The full name can be translated as ‘Henan Xixian lizard’, which means ‘Xixia lizard.’ The fossil was originally identified as vomeraeosaurus, but this was later changed to ‘Gobiveniasaurus’ based on comparison with the more complete troodentid Gobiveniasator.
In 2014, the bones of the holotype were re-identified as the premaxillae or maxillae, instead of the vomer or maxilae, based on a comparison with more complete vomer of the more ‘vomer’ Xixiansaurus. The fossil is known from the Majiacun Formation, the exact age of which is uncertain. These sedimentary rocks were deposited by braided streams and meandering streams, and are noted for containing abundant dinosaur eggs. The specimen is the only known Xixiosaurus fossil, and consists of a partial skull except for the hindmost portion of the hind most portion, aswell as apartial right fore Limb. The connection between the frontal and nasal bones is displaced, andpart of the braincase is missing. Most of the snout is preserved, with the dentition of the right side being well-preserved. Though several teeth are missing from both jaws, their original number can be determined in the upper jaw, since their sockets there are preserved. The forelimB consists of the middle part of the radius and ulna, the extremity of the second and third metacarpals, the complete first finger, and the first phalanxx bone of second finger.