Magnosaurus is a genus of dinosaur belonging to the group Megalosauridae. It lived during the Middle Jurassic period, approximately 170 to 165 million years ago. The first fossils of Magnosaurus were discovered in England, making it a significant find for the study of prehistoric life in Europe.

Before the 1990s, the genus was considered a species of Megalosaurus. However, due to increasing uncertainty surrounding the definition of Megalosaurus, Magnosaurus has now been recognized as a distinct genus. Morphological differences also support this separation; for instance, the tibiae of possible Megalosaurus specimens are compressed at the far end, while those of Magnosaurus exhibit different characteristics.

Magnosaurus was a fearsome predator, measuring around 20 to 25 feet (6 to 8 meters) in length. As a member of the megalosaurid group, it exhibited some defining features that set it apart from other dinosaurs.

One of the most notable characteristics of Magnosaurus was its powerful jaws, equipped with sharp, serrated teeth. These teeth, along with its robust skull and strong limbs, suggest that it was an active and efficient predator, capable of taking down a variety of prey.