Paleontology is a fascinating field that utilizes an array of meticulous methods to best depict what the creatures of old were like: extinct dinosaurs, mammals, reptiles, you name it. However, even though scientists have come a long way in this area, it doesn’t mean it was a smooth road. And through the years, there have been more than a few mistakes, and sometimes a mistake is so significant, it changes how we think about a certain animal, but the silver lining (as seen with these 4 creatures) is that these giant mishaps make for interesting discussions.