Apatosaurus of gigantic sauropod dinosaurs. The family includes some of the longest creatures ever to walk the earth, including "Diplodocus", "Supersaurus", and "Barosaurus". "Apatosaurus" is sometimes classified in the subfamily Apatosaurinae, which may also include "Suuwassea", "Supersaurus", and "Brontosaurus". Othniel Charles Marsh described "Apatosaurus" as allied to "Atlantosaurus" within the now-defunct group Atlantosauridae. In 1878 Marsh raised his family to the rank of suborder, including "Apatosaurus", "Atlantosaurus", "Morosaurus" (="Camarasaurus") and "Diplodocus". He classified this group within Sauropoda, a group he erected in the same study. In 1903 Elmer S. Riggs said the name Sauropoda would be a junior synonym of earlier
Apatosaurus was found a short distance from a skeleton (specimen CM3018) identified as the new species "Apatosaurus louisae", named after Louise Carnegie, wife of Andrew Carnegie, who funded field research to find complete dinosaur skeletons in the American West. The skull was designated CM11162; it was very similar to the skull of "Diplodocus". Another smaller skeleton of "A.louisae" was found nearby CM11162 and CM3018. The skull was accepted as belonging to the "Apatosaurus" specimen by Douglass and Carnegie Museum director William H. Holland, although other scientistsmost notably Osbornrejected this identification. Holland defended his view in 1914 in an address to the