The form was variously cited over the years as Diclonius mirabilis, Hadrosaurus mirabilis, Trachodon mirabilis, Claosaurus annectens, Trachodon annectens, Thespesius annectens, Anatosaurus copei, Anatosaurus annectens, Edmontosaurus annectens, and, finally, Anatotitan copei!

When Anatosaurus  was found to be a junior synonyum of Edmontosaurus a new genus name was given to Anatosaurus copei because it differs in such a way that it couldn't remain whitin that genus . The new genusname for this species became Anatotitan copei. Anatosaurus copei became famous trough several paintings and plastic models as Trachodon.