Yunnanosaurus is an extinct sauropodomorph dinosaur genus that thrived around 199 to 183 million years ago in what is now China's Yunnan Province, the source of its name. Yunnanosaurus was a sizable quadrupedal herbivore with a moderately-built body structure, capable of both bipedal and quadrupedal locomotion. It ranged in size from approximately 7 meters (23 feet) in length and 2 meters (6.5 feet) in height to as tall as 4 meters (13 feet) in the largest species.

Yunnanosaurus had over sixty spoon-shaped teeth in its jaws, a distinct feature among early sauropodomorphs. These teeth were unique in that they self-sharpened due to their interaction as the animal fed, a characteristic not observed in other contemporaneous species. These teeth are considered advanced compared to those of other early sauropodomorphs, sharing similarities with those found in sauropods. However, despite this dental resemblance, Yunnanosaurus is not considered closely related to sauropods in terms of evolutionary lineage, primarily because its remaining anatomical features are notably consistent with the "prosauropod" design.