Monolophosaurus ("single crested lizard") was a theropod dinosaur from Asia; it was famous for its crest.
There is some doubt about where Monolophosaurus belongs - some scientists think that it is an early species of a carnosaur, while others think that it is more closely related to megalosaurs instead. The only skeleton ever found was that of a 5 meter (16 foot) long juvenile. Adults would have been somewhat bigger.
Unlike other crested theropods, such as Cryolophosaurus or Dilophosaurus, the crest of Monolophosaurus was hollow on the inside and connected with its nasal passages. This might have made Monolophosaurus' respiratory system more effective, or allowed it communicate in a style similar to the hadrosaurs of the Cretaceous.
Monolophosaurus is one of the dinosaurs featured in this app.