Editing Allosaurus (section)

==Classification==
[[File:Allosaurus anax.png|thumb|right|upright=0.9|Life restoration of ''A. anax'']]
''Allosaurus'' was an allosaurid, a member of a [[Family (biology)|family]] of large theropods within the larger group [[Carnosauria]]. The family name [[Allosauridae]] was created for this genus in 1878 by [[Othniel Charles Marsh]],<ref name="OCM78">{{cite journal |last=Marsh |first=Othniel Charles |author-link=Othniel Charles Marsh |year=1878 |title=Notice of new dinosaurian reptiles |url=https://zenodo.org/record/1450042 |journal=American Journal of Science and Arts |volume=15 |issue=87 |pages=241–244 |bibcode=1878AmJS...15..241M |doi=10.2475/ajs.s3-15.87.241 |s2cid=131371457 |archive-date=August 18, 2020 |access-date=June 28, 2019 |archive-url=https://web.archive.org/web/20200818111419/https://zenodo.org/record/1450042 |url-status=live }}</ref> but the term was largely unused until the 1970s in favor of [[Megalosauridae]], another family of large theropods that eventually became a [[wastebasket taxon]]. This, along with the use of ''Antrodemus'' for ''Allosaurus'' during the same period, is a point that needs to be remembered when searching for information on ''Allosaurus'' in publications that predate James Madsen's 1976 monograph. Major publications using the name "Megalosauridae" instead of "Allosauridae" include [[Charles W. Gilmore|Gilmore]], 1920,<ref name=CWG20/> [[Friedrich von Huene|von Huene]], 1926,<ref name=FvH26>{{cite journal |last=von Huene |first=Friedrich |year=1926 |title=The carnivorous Saurischia in the Jura and Cretaceous formations, principally in Europe |journal=Revista del Museo de La Plata |volume=29 |pages=35–167}}</ref> [[Alfred Sherwood Romer|Romer]], 1956 and 1966,<ref name=ASR56>{{cite book |last=Romer |first=Alfred S. |year=1956 |title=Osteology of the Reptiles |publisher=University of Chicago Press |location=Chicago |isbn=978-0-89464-985-1}}</ref><ref name=ASR66>{{cite book |last=Romer |first=Alfred S. |title= Vertebrate Paleontology |url=https://archive.org/details/vertebratepaleon0000rome_q8n3 |url-access=registration |edition=Third |year=1966 |publisher= University of Chicago Press |location= Chicago |isbn=978-0-7167-1822-2}}</ref> Steel, 1970,<ref name=Steel70>{{cite journal|last=Steel|first=R.|year= 1970|title=Part 14. Saurischia. Handbuch der Paläoherpetologie/Encyclopedia of Paleoherpetology|journal= Gustav Fischer Verlag, Stuttgart|pages=1–87}}</ref> and [[Alick Walker|Walker]], 1964.<ref name=ADW64>{{cite journal |last=Walker |first=Alick D. |year=1964 |title=Triassic reptiles from the Elgin area: ''Ornithosuchus'' and the origin of carnosaurs |journal=Philosophical Transactions of the Royal Society B |volume=248 |pages=53–134 |issue=744 |doi=10.1098/rstb.1964.0009 |bibcode=1964RSPTB.248...53W |jstor=2416617|s2cid=86378219 }}</ref>

Following the publication of Madsen's influential monograph, Allosauridae became the preferred family assignment, but it too was not strongly defined. Semi-technical works used Allosauridae for a variety of large theropods, usually those that were larger and better-known than megalosaurids. Typical theropods that were thought to be related to ''Allosaurus'' included ''[[Indosaurus]]'', ''[[Piatnitzkysaurus]]'', ''[[Piveteausaurus]]'', ''[[Yangchuanosaurus]]'',<ref name=DL83>{{cite book |last1=Lambert |first1=David |last2=the Diagram Group |title=A Field Guide to Dinosaurs |year=1983 |publisher=Avon Books |location=New York |isbn=978-0-380-83519-5 |chapter=Allosaurids |pages=[https://archive.org/details/fieldguidetodino00lamb/page/80 80–81] |chapter-url=https://archive.org/details/fieldguidetodino00lamb/page/80 }}</ref> ''[[Acrocanthosaurus]]'', ''[[Chilantaisaurus]]'', ''[[Compsosuchus]]'', ''[[Stokesosaurus]]'', and ''[[Szechuanosaurus]]''.<ref name=DL90>{{cite book |last1=Lambert |first1=David |last2=the Diagram Group |title=The Dinosaur Data Book |year=1990 |publisher=Avon Books |location=New York |isbn=978-0-380-75896-8 |chapter=Allosaurids |page=[https://archive.org/details/dinosaurdatabook00lamb/page/130 130] |chapter-url=https://archive.org/details/dinosaurdatabook00lamb/page/130 }}</ref> Given modern knowledge of theropod diversity and the advent of cladistic study of [[evolution]]ary relationships, none of these theropods is now recognized as an allosaurid, although several, like ''Acrocanthosaurus'' and ''Yangchuanosaurus'', are members of closely related families.<ref name=HMC04/>
[[File:Allosaurus jimmadseni skull illustration.png|thumb|Illustrations showing the skull of ''A. jimmadseni'' from the side (A), top (B), and back (C)]]
[[File:WLA hmns Allosaurus.jpg|thumb|''A. jimmadseni'' specimen "Big Al II" (SMA 0005)]]
Below is a cladogram based on the analysis of Benson et al. in 2010.<ref name="bensonetal2010">{{cite journal |last1=Benson |first1=R.B.J. |last2=Carrano |first2=M.T. |last3=Brusatte |first3=S.L. |author-link3=Stephen L. Brusatte |year=2010 |title=A new clade of archaic large-bodied predatory dinosaurs (Theropoda: Allosauroidea) that survived to the latest Mesozoic |url=https://repository.si.edu/bitstream/handle/10088/8609/paleo_Benson_10.pdf |journal=Naturwissenschaften |volume=97 |issue=1 |pages=71–78 |bibcode=2010NW.....97...71B |doi=10.1007/s00114-009-0614-x |pmid=19826771 |s2cid=22646156 |archive-date=August 31, 2021 |access-date=August 6, 2018 |archive-url=https://web.archive.org/web/20210831103656/https://repository.si.edu/bitstream/handle/10088/8609/paleo_Benson_10.pdf |url-status=live }}</ref>

{{clade| style=font-size:100%; line-height:100%
|label1=[[Allosauroidea]]
|1={{clade
 |1=[[Sinraptoridae]] [[File:Alpkarakush UDL.png|80px]]
 |2={{clade
   |1='''''Allosaurus''''' <span style="{{MirrorH}}">[[File:Allosaurus anax.png|80px]]</span>
   |2={{clade
      |1={{clade
         |1=''[[Neovenator]]'' <span style="{{MirrorH}}">[[File:Neovenator.png|80px]]</span>
         |2={{clade
            |1=''[[Fukuiraptor]]'' 
            |2=''[[Megaraptor]]'' <span style="{{MirrorH}}">[[File:MegaraptorNV.jpg|80px]]</span> }} }}
      |2={{clade
         |1=''[[Eocarcharia]]''
         |2={{clade
            |1=''[[Acrocanthosaurus]]'' <span style="{{MirrorH}}">[[File:Acrocanthosaurus restoration.jpg|80px]]</span>
            |2={{clade
               |1=''[[Shaochilong]]'' <span style="{{MirrorH}}">[[File:Shaochilong.jpg|80px]]</span>
               |2={{clade
                  |1=''[[Tyrannotitan]]''
                  |2={{clade
                     |1=''[[Carcharodontosaurus]]'' [[File:Carcharodontosaurus UDL.png|80px]]
                     |2=''[[Giganotosaurus]]'' [[File:Giganotosaurus BW.jpg|80px]]
                     |3=''[[Mapusaurus]]'' [[File:Mapusaurus BW.jpg|80px]] }} }} }} }} }} }} }} }} }}

Allosauridae is one of four families in Allosauroidea; the other three are [[Neovenatoridae]],<ref name="bensonetal2010"/> [[Carcharodontosauridae]] and [[Sinraptoridae]].<ref name="HMC04"/> Allosauridae has at times been proposed as ancestral to the [[Tyrannosauridae]] (which would make it [[Paraphyly|paraphyletic]]), one example being Gregory S. Paul's ''Predatory Dinosaurs of the World'',<ref name="GSP88c">Paul, Gregory S. (1988). "The allosaur-tyrannosaur group", ''Predatory Dinosaurs of the World''. 301–347.</ref> but this has been rejected, with tyrannosaurids identified as members of a separate branch of theropods, the [[Coelurosauria]].<ref name="TRHJ94">{{cite journal|last=Holtz |first=Thomas R. Jr. |year= 1994 |title=The phylogenetic position of the Tyrannosauridae: Implications for theropod systematics |journal=Journal of Paleontology |volume=68 |issue=5 |pages=1100–1117 |jstor=1306180|doi=10.1017/S0022336000026706 |bibcode=1994JPal...68.1100H |s2cid=129684676 }}</ref> Allosauridae is the smallest of the carnosaur families, with only ''Saurophaganax'' and a currently unnamed French [[Allosauroidea|allosauroid]] accepted as possible valid [[Genus|genera]] besides ''Allosaurus'' in the most recent review.<ref name="HMC04"/> Another genus, ''Epanterias'', is a potential valid member, but it and ''Saurophaganax'' may turn out to be large examples of ''Allosaurus''.<ref name="GSP88"/> Some reviews have kept the genus ''[[Saurophaganax]]'' and included ''Epanterias'' with ''Allosaurus''.<ref name="HMC04"/><ref name="JRF03"/>

The controversial ''Saurophaganax'', initially recognized as a large ''Allosaurus''-like theropod, has had a controversial taxonomic history. In 2019, Rauhut and Pol noted that its taxonomic placement within [[Allosauroidea]] is unstable, being recovered as a sister taxon of [[Metriacanthosauridae]] or Allosauria, or even as the basalmost carcharodontosaurian.<ref name="Rauhut2019">{{Cite journal|last1=Rauhut|first1=Oliver W. M.|last2=Pol|first2=Diego|date=December 11, 2019|title=Probable basal allosauroid from the early Middle Jurassic Cañadón Asfalto Formation of Argentina highlights phylogenetic uncertainty in tetanuran theropod dinosaurs|journal=Scientific Reports|language=en|volume=9|issue=1|pages=18826|doi=10.1038/s41598-019-53672-7|pmid=31827108|pmc=6906444|bibcode=2019NatSR...918826R |issn=2045-2322}} [https://www.nature.com/articles/s41598-019-53672-7#MOESM1 Supplementary information] {{Webarchive|url=https://web.archive.org/web/20241007165345/https://www.nature.com/articles/s41598-019-53672-7#MOESM1 |date=October 7, 2024 }}</ref> In 2024, ''Saurophaganax'' was reassessed as a [[nomen dubium|dubious]], [[chimera (paleontology)|chimeric]] taxon with the holotype being so fragmentary that it could only be confidently referred to the [[Saurischia]], and some specimens more likely belonging to a [[diplodocid]] [[sauropod]].<ref name="DEA24"/>