Gasosaurus was a tetanuran dinosaur exposed in Dashanpu, China. It had strong legs but short arms, and powerful jaws point to that it was a carnivore. It measured between 3.5 and 4 meters in length and 1.3m in height, with a weight of approximately 150[kg], placing it in the midrange of carnivores by size. However, some estimates put its weight as high as 400kg, as very little is known about this dinosaur. It lived throughout Bathonian and Callovian periods (mid-late Jurassic), around 164 million years ago. By analogy with additional tetanurans, it probably hunted in packs.

The first and to date only fossils, albeit postcranial (missing the skull), were healthier in 1985 during the construction of a gas facility. This explains the unusual name, which literally means gas lizard. These fossils were defined as the category species Gasosaurus constructs by the paleontologists Dong Zhiming and Tang Zilu. There have still been very few fossils retrieved, so its precise details are unknown. Specifically, no skull has been established, and some paleobotanists have speculated that Gasosaurus and Kaijiangosaurus may be one and the same species. A relation to Megalosaurus has also been suggested. Also, although present consensus is to place Gasosaurus in the group Carnosauria, it may in fact be the most basal Coelurosaurian yet known, or even be a common ancestor of the two groups.