Sinosaurus is a genus of dinosaur that lived during the Jurassic period, approximately 165 to 150 million years ago. As a theropod, it belongs to the group of carnivorous dinosaurs, characterized by their bipedal stance, sharp teeth, and predatory nature. The name "Sinosaurus" is derived from "Sino," referring to China, and "saurus," meaning "lizard," acknowledging its origin and classification.

The fossil remains of Sinosaurus were first discovered in the Yunnan Province of southwestern China.

As a theropod dinosaur, Sinosaurus exhibited typical characteristics of the group. It walked on two powerful hind limbs, supported by a long tail that provided balance and stability during locomotion. Its forelimbs were relatively small and ended in sharp claws, which were likely used for grasping and capturing prey.

The size of Sinosaurus remains a subject of study due to incomplete fossil evidence. Based on comparisons with other theropods, it is estimated to have measured around 18 to 30 feet (5.5 to 9 meters) in length. Its weight is estimated to be around 300 kg (660 lbs).

Initially Sinosaurus was believed to be a coelophysoid dinosaur with close affinities to Dilophosaurus and Cryolophosaurus, a 2003 study revealed that Sinosaurus is actually a more advanced theropod, showing a relationship to Cryolophosaurus and "Dilophosaurus" sinensis.