Monolophosaurus was a medium-sized theropod dinosaur that lived during the Middle Jurassic period, around 165 million years ago. It measured about 5 to 7 meters (16 to 23 feet) in length and is known for the distinctive single crest running along the top of its skull, which likely served for species recognition or display. Monolophosaurus was a carnivore, equipped with sharp teeth and powerful jaws for hunting other dinosaurs. Its fossils were discovered in China, providing important information about the diversity of theropods during the Jurassic and offering insights into the early evolution of large predatory dinosaurs in Asia.