Now and then: Megalosaurus

Finally, the dinosaur that started as a ballsack. The first one is the famous Crystal Palace Megalosaurus, the morphotype that was the prevalent conception of this dinosaur in the 19th century when only very few skeletal elements of theropods were known (actually, at first Megalosaurus was considered a huge lizzard, but I found no illustration of that idea). It kind of looks like a mix of bear and crocodile. By the later half of the 19th century, more became known about the anatomy of non-avian theropods and non-avian dinosaurs in general, and the drawing at the top right shows what was considered a megalosaur until the 1980s. During the 1980s until the 2010s, let's call it the Bakker-Paulian era, megalosaurs were, just like all non-avian dinosaurs, restored in a rather skinny, lanky manner with pronated hands. Nowadays, this morph is considered incorrect, and modern reconstructions (bottom left) better appreciate the muscling of the animal. The hands aren't pronated, and the nostrils at the anteriormost place of the nasal opening. Also, many paleoartists today assume that theropods had lipped jaws covering the teeth. 
Scott Hartman's skeletal drawings are the references for the two drawings at the bottom.