Apatosaurus considered a junior synonym of "Apatosaurus"; its only species was reclassified as "A.excelsus" in 1903. A 2015 study concluded that "Brontosaurus" is a valid genus of sauropod distinct from "Apatosaurus", but not all paleontologists agree with this division. As it existed in North America during the late Jurassic, "Apatosaurus" would have lived alongside dinosaurs such as "Allosaurus", "Camarasaurus", "Diplodocus", and "Stegosaurus". "Apatosaurus" was a large, long-necked, quadrupedal animal with a long, whip-like tail. Its forelimbs were slightly shorter than its hindlimbs. Most size estimates are based on specimen CM3018, the type specimen of "A.louisae". In 1936 this was measured to
Alan the Dinosaur Alan the Dinosaur Alan the Dinosaur is the name given to an unidentified Sauropodomoph fossil, found in Whitby in 1995, regarded as the oldest sauropod dinosaur found in the United Kingdom. It is now in the Yorkshire Museum. The fossil was discovered in Whitby in 1995 by Alan Gurr whilst on a field trip to the site led by geologist Phil Manning. A chunk of sandstone fell from cliff face and was inspected by the finder, who spotted the fragment of vertebra. As it is not identifiable to species level, it gained the nickname 'Alan' in commemoration of its finder.