Three Jurassic dinosaurs that have experienced name changes for various reasons over the years. Apatosaurus (Brontosaurus) OC Marsh again. He was responsible for both names but didn't realise when he named Brontosaurus that he was dealing with the same dinosaur he had named a year earlier. This was possibly because the earlier find was of a juvenile and the latter of an adult. Because of palaeontological naming traditions the first name it is given has priority. (Unless it happens to be T.Rex of course-see previous entry under 'What's in a Name). Allosaurus (Antrodemus) Interestingly the reverse seems to be true for Allosaurus. Antrodemus valens was described by Joseph Leidy in 1870 from fragments of tail verterbrae discovered in the upper Jurassic Morrison formation rocks in Colorado. Seven years later OC Marsh described another discovery from the Morrison formation near Canon City, Colorado as Allosaurus fragilis. Skip forward over four decades and Charles Gilmore, another American palaeontologist decided that Allosaurus bones were indistinguishable from Antrodemus and because of this it should now be referred to as Antrodemus. This remained the case for about half a century until the 1970's when James Madsen made a case that because of the poor diagnostic quality of the material that Antrodemus was derived from that the beast should now be called Allosaurus. Which just goes to show that black and white aren't always black and white. Giraffatitan (Brachiosaurus) The final name change. Brachiosaurus still exists as a genus and describes a north American Sauropod from the morrison formation described by Elmer Riggs in 1903. However, for much of the last century when text books described brachiosaurus they were referring to a later discovery made by German paleontologist Werner Janensch in the Tendaguru formation in Tanzania. Janensch believed he had discovered an African version of Brachiosaurus; it was not until 2009 and following two decades of misgivings by paleontologists that the African brachiosaurus was renamed Giraffatitan. The African genus is more massive than it's distant American cousin and when a skull was found in 1998 this further emphasised the differences between them. The Brachiosaurus (Giraffatitan) is from DAZ 3d and is by Dinoraul. The Allosaurus and Apatosaurus are also from DAZ and are by Vairesh and Digital 1 designs. Background by MN Artist