The first Monolophosaurus skeleton was discovered by a joint Canadian-Chinese expedition to Xinjiang Province of China in 1981. Although a few more partial skeletons have been found, Monolophosaurus remains a rare dinosaur.
The most conspicuous characteristic of Monolophosaurus is the single crest on the top of the animal’s head. Although Monolophosaurus looks a bit like the more famous Tyrannosaurus rex, it is much smaller and more primitive. Although it is bipedal, its front limbs are still quite large, and the hands still have three strong fingers that would have been useful in grasping prey. In these characteristics, it is more similar to, and more closely related to more primitive theropods like Allosaurus and Ceratosaurus.