You mean Brontosaurus is not real? That’s right. In 1877, the famous American fossil hunter, Othniel Marsh, found a hip and a few backbones from a dinosaur that came to be called Apatosaurus. Then, two years later, he found the skeleton of another dinosaur, and named it Brontosaurus. However, in 1903 a scientist discovered that Brontosaurus was just an adult version of Apatosaurus. According to the rules of naming at the time, Apatosaurus is the correct name, since this name came first. But, because people had gotten so used to calling the animal Brontosaurus (and because, to most people, Brontosaurus "sounds better" than Apatosaurus), most people today still use the name Brontosaurus. But remember, Apatosaurus is the proper scientific name.