| Named By: | Ji, Q. & Ji, S. in 1996 |
| Time Period: | Early Cretaceous, 124.6-122 Ma |
| Location: | China, Liaoning Province - Yixian Formation |
| Size: | Up to 107 centimetres long |
| Diet: | Carnivore |
| Fossil(s): | Three known specimens. Some specimens are so well preserved they show internal organs and prey |
| Classification: | | Chordata | Reptilia | Dinosauria | Saurischia | Theropoda | Compsognathidae | |
Sinosauropteryx (meaning "Chinese reptilian wing", Chinese: Zhong Hua Long Niao ; pinyin: Zhonghua long niao; literally: "China dragon bird") is a compsognathid dinosaur. Described in 1996, it was the first dinosaur taxon outside of Avialae (birds and their immediate relatives) to be found with evidence of feathers. It was covered with a coat of very simple filament-like feathers. Structures that indicate colouration have also been preserved in some of its feathers, which makes Sinosauropteryx the first non-avialian dinosaurs where colouration has been determined. The colouration includes a reddish and light banded tail. Some contention has arisen with an alternative interpretation of the filamentous impression as remains of collagen fibres, but this has not been widely accepted.
Sinosauropteryx was a small theropod with an unusually long tail and short arms. The longest known specimen reaches up to 1.07 metres (3.51 feet) in length, with an estimated weight of 0.55 kilograms (1.21 pounds) It was a close relative of the similar but older genus Compsognathus, both genera belonging to the family Compsognathidae. Only one species of Sinosauropteryx has been named: S. prima, meaning "first" in reference to its status as the first feathered non-avialian dinosaur species discovered. Three specimens have been described. The third specimen previously assigned to this genus represents either a second, as-yet unnamed species or a distinct, related genus.
Sinosauropteryx lived in what is now northeastern China during the early Cretaceous period. It was among the first dinosaurs discovered from the Yixian Formation in Liaoning Province, and was a member of the Jehol Biota. Well-preserved fossils of this species illustrate many aspects of its biology, such as its diet and reproduction.