Marshosaurus was discovered in the Morrison Formation of Utah and Colorado in the 1960s. Classified as a theropod, this medium-sized dinosaur lived in North America during the Late Jurassic period. Like several other dinosaurs found in North America, Marshosaurus walked on two legs and had short arms.
Paleontologists estimate that Marshosaurus was roughly fifteen feet long and weighed nearly five hundred pounds. It had a large skull that was more than two feet long. Marshosaurus was a carnivore and excellent at hunting. This dinosaur lived in a wet environment in areas rich in fungi, green algae, ferns, and other vegetation.