Huaxiagnathus
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| Huaxiagnathus Fossil range: Early Cretaceous |
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Huaxiagnathus is a genus of theropod dinosaur from the Lower Cretaceous of China. It was a compsognathid, large for that family at about half a meter longer than Compsognathus and larger specimens of Sinosauropteryx, with the largest specimen about 1.8 meters (6 feet) in length.
The name Huaxiagnathus is derived from the Mandarin Hua Xia, meaning "China", and Greek gnathus, meaning "jaw."
[edit] Description
The holotype (CAGS-IG-02-301, Chinese Academy of Geological Sciences, Beijing) specimen was collected from the Yixian Formation (Jehol Group, Barremian) at Dabangou Village, Sihetun area, near Beipiao City, in western Liaoning Province. The holotype consists of an essentially complete skeleton, lacking only the distal portion of the tail, preserved on five large slabs. A second specimen (NGMC 98-5-003, National Geological Museum of China, Beijing) of Huaxiagnathus is known from the Yixian Formation of the Sihetun area, but damage and mistakes made during its preparation rendered it unsuitable as a holotype.
Cladistic analysis indicates that Huaxiagnathus is the basalmost known compsognathid, as indicated by its unspecialized forearm.
Hwang et al. (2004, pp. 14-15) diagnosed this genus as follows: differing from all other known compsognathids in having a very long posterior process of the premaxilla that overlaps the antorbital fossa, a manus equal to the combined lengths of the humerus and radius, large manual unguals I and II which are subequal in length and 167% the length of manual ungual III, a first metacarpal which has a smaller proximal transverse width than the second metacarpal, and the presence of a reduced olecranon process on the ulna.[1]
[edit] References
- ^ Hwang, S. H., Norrell, M. A., Qiang, J., and Keqin, G. (2004). "A large compsognathid from the Early Cretaceous Yixian Formation of China." Journal of Systematic Palaeontology, 2(1): 13-30.
