- Superorder: Dinosauria
- Order: Saurischia
- Suborder: Theropoda
- Family: None
Only the front limb and six primitive-looking vertebrae of this dinosaur have been discovered. But they are so different from other theropods that in 1984 Chinese paleontologist Dong Zhiming named the new genus Xuanhanosaurus after the type species, Xuanhanosaurus quiliziansis, for them.
Named after Xuanhan County Sichuan Basin where it was found, this theropod lived at the same time as the better-known theropod Gasosaurus, the stegosaur Huayangosaurus, and the sauropods Shunosaurus and Datousaurus. Dong at first classified Xuanhanosaurus in the family Megalosauridae, but Paleontologists now believe it requires its own family.
The arm of Xuanhanosaurus was about the same size as the arm of the later theropod Allosaurus, but it was more robustly built. The third finger was slender and it also probably had a claw but it was not found with a skeleton. A fourth finger was only a single small bone that was most likely imbedded in the palm of the hand and not visible in the living animal. It did not have a grasping hand. The shoulder bones and the breastbone were large, which suggests that Xuanhanosaurus sometimes used its arms for walking.
Scientists are hoping to find more fossils of Xuanhanosaurus so They have more information to study. More fossils may also give clues as to which family this unusual dinosaur belongs to.