Editing Diplodocidae (section)

==Classification==
[[File:Dinosaurs in Their Time- Jurassic Era Room (2705542612).jpg|left|thumb|Holotype specimens of ''Diplodocus carnegii'' and ''Apatosaurus louisae'' at [[Carnegie Museum of Natural History]]]]
Diplodocidae was the third name given to what is now recognized as the single family of long-necked, whip-tailed sauropods. [[Edward Drinker Cope]] named the family '''Amphicoeliidae''' in 1878 for his genus ''[[Amphicoelias]]'', sometimes considered a diplodocid.<ref name="Carpenter2006"/> However, the name Amphicoeliidae did not come into wider use and was not used in the scientific literature after 1899, making it a ''[[nomen oblitum]]'' ("forgotten name") according to the [[International Code of Zoological Nomenclature|ICZN]], preventing it from displacing the name Diplodocidae as a senior synonym.<ref name="Olshevsky1991"/> More recent studies have also shown that ''Amphicoelias'' itself does not belong to this family, but is instead a more primitive diplodocoid.<ref name="Whitlock2011"/> A similar situation occurred for the family name '''Atlantosauridae''', named by [[Othniel Charles Marsh]] in 1877, and which Hay argued had priority over Amphicoelidae.<ref name="Hay1902"/> George Olshevsky declared Atlantosauridae a ''nomen oblitum'' in 1991, though scientists such as Steel and Nowinski had treated Atlantosauridae as a valid name as late as 1971, and the former even added a subfamily, '''Atlantosaurinae'''.<ref name="Olshevsky1991"/><ref name="Nowinski1971"/>

Some dinosaurs have been considered diplodocids in the past but have not been found to be members of that group in later, larger analyses of the family's relationships. ''[[Australodocus]]'', for example, was initially described as a diplodocid, but may actually have been a [[Macronaria]]n.<ref name="Whitlock2011"/><ref name="Remes2007"/> ''Amphicoelias'' was traditionally considered a diplodocid due to its similar anatomy, but phylogenetic studies showed it to be a more basal member of the Diplodocoidea.<ref name="Whitlock2011"/>

The relationships of species within Diplodocidae has also been subject to frequent revision. A study by Lovelace, Hartman and Wahl in 2008 found that ''[[Suuwassea]]'' and ''Supersaurus'' were relatives of ''Apatosaurus'', within the subfamily Apatosaurinae. However, a subsequent analysis by Whitlock in 2011 showed that ''Supersaurus'' is slightly closer to ''Diplodocus'' than to ''Apatosaurus'', and that ''Suuwassea'' is actually a primitive [[Dicraeosauridae|dicraeosaurid]].<ref name="Whitlock2011"/>
[[File:Apatosaurus Clean.png|thumb|Cast skeleton of ''Brontosaurus parvus'' based on the University of Wyoming specimen produced by [[Triebold Paleontology Incorporated]]]]
The subfamily '''Diplodocinae''', was erected to include ''Diplodocus'' and its closest relatives, including ''[[Barosaurus]]''.<ref name="TaylorNaish2005"/><ref name="Harris2006"/> The Portuguese ''[[Dinheirosaurus]]'' and the African ''[[Tornieria]]'' have also been identified as close relatives of ''Diplodocus'' by some authors.<ref name="BonaparteMateus1999"/><ref name="Rauhut2005"/>

[[Cladogram]] of the Diplodocidae after Tschopp, Mateus, and Benson (2015).<ref name="Tschopp2015"/>
{{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=''[[Supersaurus 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]]''
}} }} }} }} }} }} }} }} }} }}