Editing Apatosaurus (section)

==Classification==
[[File:Apatosaurus ajax scapulocoracoid.jpg|thumb|upright|Shoulder blade and [[coracoid]] of ''A. ajax'']]
''Apatosaurus'' is a member of the [[family (biology)|family]] [[Diplodocidae]], a [[cladistics|clade]] of gigantic [[sauropod]] [[dinosaur]]s. 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''.<ref name=LHW07/><ref name="taylornaish05"/><ref name="harris06"/> [[Othniel Charles Marsh]] described ''Apatosaurus'' as allied to ''Atlantosaurus'' within the now-defunct group [[Atlantosauridae]].<ref name="riggs-1903"/><ref name="marsh1877"/> 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 names; he grouped ''Apatosaurus'' within [[Opisthocoelia]].<ref name="riggs-1903"/> Sauropoda is still used as the group name.<ref name="Upchurch05"/> In 2011, John Whitlock published a study that placed ''Apatosaurus'' a more [[basal (phylogenetics)|basal]] diplodocid, sometimes less basal than ''Supersaurus''.<ref name="whitlock2011"/><ref name="gallinaetal2014"/>

[[Cladogram]] of the Diplodocidae after Tschopp, Mateus, and Benson (2015).<ref name="TMB2015"/>
{{clade| style=font-size:85%;line-height:85%
|label1=[[Diplodocidae]]
|1={{clade
   |1=''[[Amphicoelias altus]]''
   |2={{clade
      |label1=[[Apatosaurinae]]
      |1={{clade
         |1=Unnamed species
         |2={{clade
            |1={{clade
               |1='''''Apatosaurus ajax'''''
               |2='''''Apatosaurus louisae''''' }}
            |2={{clade
               |1=''[[Brontosaurus excelsus]]''
               |2={{clade
                  |1=''[[Brontosaurus yahnahpin]]''
                  |2=''[[Brontosaurus parvus]]'' }} }} }} }}
      |label2=[[Diplodocinae]]
      |2={{clade 
         |1=Unnamed species
         |2={{clade
            |1=''[[Tornieria africana]]''
            |2={{clade
               |1={{clade
                  |1=''[[Dinheirosaurus lourinhanensis]]''
                  |2=''[[Supersaurus vivianae]]'' }}
               |2={{clade
                  |1=''[[Leinkupal laticauda]]''
                  |2={{clade
                     |1=''[[Galeamopus hayi]]''
                     |2={{clade
                        |1={{clade
                           |1=''[[Diplodocus carnegii]]''
                           |2=''[[Diplodocus hallorum]]'' }}
                        |2={{clade
                           |1=''[[Kaatedocus siberi]]''
                           |2=''[[Barosaurus lentus]]''
}} }} }} }} }} }} }} }} }} }}