Marsh, in a hasty note typical of the current race between him and Edwin D. Cope, describes Brontosaurus, but in reality it is still the Apatosaurus ajax, also described by him a few years earlier. The enormous amount of specimens discovered in just a few years by Marsh and Cope in North America does not allow the error to be immediately noticed, and this will create confusion between the two names (the scientific one is Apatosaurus ajax, but in popular culture it is Brontosaurus).
