Linheraptor
Live reconstruction of Linheraptor exquisitus.
- Inner Mongolia, China ( Wulansuhai Formation)
- Linheraptor exquisitus
Linheraptor was a genus of small carnivorous dinosaur from the group of Dromaeosauridae. So far, a single, well-preserved and nearly complete skeleton is known, which dates from the Wulansuhai formation of the Chinese province of Inner Mongolia and about 83.6 to 72 million years old ( Campanian ). This genus was described in 2010 with the only kind Linheraptor exquisitus scientifically.
Features
Linheraptor is estimated to have a length of 1.8 meters and was similar in size to Velociraptor. The hull is estimated to be 36.5 cm in length from the first vertebra to the acetabulum ( pelvis socket ). The skeleton is probably derived from an adult individual, let what fusions of the vertebrae and the tibiotarsus ( lower leg ) close. The skull was 22.5 cm long and seems to be narrower than that of the closely related Tsaagan - but this difference could be caused by deformation of the skull. To show various skull of Velociraptor considerable variations in skull proportions. The dentition is poorly preserved, so the number of teeth is not exactly determined. However, half of the lower jaw ( dentary ) contributed about 15 teeth, similar to many as Tsaagan and Velociraptor. The front sides of the teeth were ungesägt as Tsaagan and many basal Dromaeosauriden.
The S -shaped curved neck consisted of 10 cervical vertebrae. As with most other Dromaeosauriden the tail pointed strongly elongated spinous processes on ( postal and prezygapophyses and chevron bones). The humerus (humerus ) accounts for less than 70 % of the length of the thigh bone (femur) of. As with all Dromaeosauriden the second toe was a characteristic enlarged sickle claw.
Linheraptor was probably closer to Tsaagan used as with other Dromaeosauriden. Tsaagan is known only by a skull and the front eight cervical vertebrae. Both genera have some features in common, the other Dromaeosauriden missing: For example, the Maxillarfenster is significantly increased and similar in size to the nostrils; In addition to zygomatic ( Jugale ) and squamosal contact ( squamosal ) so that the postorbital is excluded from the infra pace Ralf Rochester. Other features demarcate Linheraptor of Tsaagan: for example, showed the Axis, the second cervical vertebra, a large pneumatic opening ( foramen ) on the lateral surface of the vertebral body; similar to Mahakala, Velociraptor and Deinonychus. In Tsaagan this feature is missing. Another example is the significantly lower rear end of the lower jaw of Linheraptor, which causes the glenoid fossa ( glenoid fossa ) is on a level with the tooth row.
System
The descriptor suspect Linheraptor together with the closely related Tsaagan formed his own group late Cretaceous, Asian Dromaeosauriden. Both genera were phylogenetically basal as Velociraptor and were probably between basal and advanced Dromaeosauriden.
Fund and naming
The skeleton was discovered in 2008 during an expedition in Inner Mongolia in Bayan Mandahu in the district Linhe, the site was known under the name The Gate locality. The expedition was a joint expedition of two Chinese Institute, the Institute of Vertebrate Paleontology & Paleoanthropology and the Long Hao Institute of Geology and Paleontology, and aimed to improve the understanding of the dinosaur fauna of the Upper Cretaceous of Inner Mongolia. Jonah Choiniere, a student at George Washington University (Washington, DC), discovered the first bones of the skeleton: the tip of a claw, which jutted out from a cliff eroded by the wind of red sandstone.
The rocks of the discovery site belong stratigraphically to Wulansuhai lineup, the Chinese equivalent of the Mongol Djadochta lineup. From Djadochta lineup already four other Dromaeosauriden species were previously recovered: mongoliensis Velociraptor, Velociraptor osmolskae, Tsaagan mangas and Mahakala omnogovae. Thus Linheraptor is already the fifth Dromaeosauride this fauna.
The Fund ( holotype, IVPP V 16923 copy number ) is almost complete, up found in the anatomical composite skeleton. It was scientifically described by Xu Xing and colleagues in 2010. The name Linheraptor has the locality in the municipality Linhe; raptor means as much as " robbers " and underlines the status of predators. The epithet exquisitus points to the exceptional degree of preservation of the skeleton.