Yangchuanosaurus was a theropod dinosaur thought to be related to Allosaurus. Two species have been discovered: shangyouensis and zigongensis. Both of these dinosaurs lived in the Late Jurassic of China. They most likely hunted in packs. Yangchuanosaurus was essentially the Asian variant of Allosaurus, and performed exactly the same role in a parallel ecosystem to that most often attributed to North America, Europe and Africa.
Yangchuanosaurus is not physically seen in the movie. But on the map of the park and next to a vial in the Cold Storage Room the name Metriacanthosaurus is shown. According to vertebrate paleontologist Thomas R. Holtz, Jr. this was probably meant to refer to Yangchuanosaurus, which was then classified as a species of the metriacanthosaur genus (click here for a detailed discussion).
Yangchuanosaurus can be created from paleo-DNA in the game Jurassic Park III: Park Builder.
In Jurassic Park: Operation Genesis, Yangchuanosaurus was one of the many dinosaurs mentioned to have been in the game, but wound up being cut (possibly replaced by Allosaurus). However, its name can still be found in the in-game files.