Megalosaurus is a genus of large theropod dinosaur that lived during the Middle Jurassic period, around 166 to 164 million years ago. It is one of the first dinosaurs to be formally named, and was originally described by the English anatomist Richard Owen in 1824.

Megalosaurus was a large and powerful predator, measuring up to 9 meters (30 feet) in length and weighing around 1 ton. It had a long, narrow skull with sharp teeth, and strong, muscular legs with sharp claws. It likely hunted large herbivorous dinosaurs, as well as smaller animals like mammals and reptiles.

Megalosaurus was initially thought to be a reptile, but later studies showed that it was actually a dinosaur. It played an important role in the early history of dinosaur paleontology, as it was one of the first dinosaurs to be described in scientific literature. Its name, which means “great lizard,” reflects its impressive size and formidable appearance.

Today, Megalosaurus is known from numerous fossil specimens found throughout Europe, particularly in England and France. Its discovery helped to establish the idea that dinosaurs were a distinct group of animals that dominated the land during the Mesozoic Era, and it remains an important and iconic dinosaur species to this day.