Megalosaurus bucklandi

Megalosaurus was a large megalosaurid (bet you didn’t see that one coming) theropod from the Middle Jurassic of England. It was the first dinosaur to be scientifically named, in 1824, and was one of the original three members of Dinosauria when Owen named the group in 1842 (along with Iguanodon and Hylaeosaurus). Over time Megalosaurus became something of a wastebasket name for miscellaneous European predators (heck, Dilophosaurus was first described as a species of Megalosaurus!). Modern work removed the material that shouldn’t have been included, and now the famous species is represented by much more limited material, which you can see in the known-material skeletal below.