Editing Allosaurus (section)

===Early discoveries and research===
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| image1            = AMNH Allosaurus.jpg
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| caption1          = Mounted ''A. fragilis'' specimen (AMNH 5753), posed as scavenging an ''[[Apatosaurus]]''
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| caption2          = AMNH 5753 in a [[Charles R. Knight]] life restoration (Outdated)
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The discovery and early study of ''Allosaurus'' is complicated by the multiplicity of names coined during the [[Bone Wars]] of the late 19th century. The first described [[fossil]] in this history was a bone obtained secondhand by [[Ferdinand Vandeveer Hayden]] in [[1869 in paleontology|1869]]. It came from [[Middle Park (Colorado basin)|Middle Park]], near [[Granby, Colorado]], probably from [[Morrison Formation]] rocks. The locals had identified such bones as "petrified horse hoofs". Hayden sent his specimen to [[Joseph Leidy]], who identified it as half of a tail vertebra and tentatively assigned it to the European dinosaur genus ''[[Poekilopleuron]]'' as ''Poicilopleuron''{{sic}} ''valens''.<ref name="JL70">{{cite journal |last=Leidy |first=Joseph |author-link=Joseph Leidy |year=1870 |title=Remarks on ''Poicilopleuron valens'', ''Clidastes intermedius'', ''Leiodon proriger'', ''Baptemys wyomingensis'', and ''Emys stevensonianus'' |journal=Proceedings of the Academy of Natural Sciences of Philadelphia |volume=22 |pages=3–4}}</ref> He later decided it deserved its own genus, ''Antrodemus''.<ref name=JL73>{{cite journal |last=Leidy |first=Joseph |year=1873 |title=Contribution to the extinct vertebrate fauna of the western territories |journal=Report of the U.S. Geological Survey of the Territories I |pages=14–358}}</ref>

''Allosaurus'' itself is [[Holotype|based on]] [[Peabody Museum of Natural History|YPM]] 1930, a small collection of fragmentary bones including parts of three vertebrae, a rib fragment, a tooth, a toe bone, and (most useful for later discussions) the shaft of the right humerus (upper arm). [[Othniel Charles Marsh]] gave these remains the formal name ''Allosaurus fragilis'' in 1877. ''Allosaurus'' comes from the [[Ancient Greek|Greek]] words ''{{lang|grc-Latn|allos}}/{{lang|grc|αλλος}}'', meaning "strange" or "different", and ''{{lang|grc-Latn|sauros}}/{{lang|grc|σαυρος}}'', meaning "lizard" or "reptile".<ref>{{cite book|author=Liddell & Scott|year=1980|title=Greek–English Lexicon, Abridged Edition|publisher=Oxford University Press|location=Oxford|isbn=978-0-19-910207-5|oclc=17396377|url=https://archive.org/details/lexicon00lidd}}</ref> It was named 'different lizard' because its vertebrae were different from those of other dinosaurs known at the time of its discovery.<ref name="OCM77">{{cite journal |last=Marsh |first=Othniel Charles |author-link=Othniel Charles Marsh |year=1877 |title=Notice of new dinosaurian reptiles from the Jurassic formation |url=https://zenodo.org/record/1450040 |journal=American Journal of Science and Arts |volume=14 |issue=84 |pages=514–516 |bibcode=1877AmJS...14..514M |doi=10.2475/ajs.s3-14.84.514 |s2cid=130488291 |archive-date=April 20, 2021 |access-date=August 31, 2020 |archive-url=https://web.archive.org/web/20210420181422/https://zenodo.org/record/1450040 |url-status=live }}</ref><ref name=DMLomnipedia>{{cite web|url=http://www.dinosauria.com/dml/names/dinoa.htm |title=Dinosauria Translation and Pronunciation Guide A |access-date=September 11, 2007 |last=Creisler |first=Ben |date=July 7, 2003 |publisher=Dinosauria On-Line |archive-url=https://web.archive.org/web/20100105101204/http://www.dinosauria.com/dml/names/dinoa.htm |archive-date=January 5, 2010 |url-status=dead}}</ref> The species epithet ''fragilis'' is [[Latin]] for "fragile", referring to lightening features in the vertebrae. The bones were collected from the Morrison Formation of [[Garden Park, Colorado|Garden Park]], north of [[Cañon City, Colorado|Cañon City]].<ref name=OCM77/> O. C. Marsh and [[Edward Drinker Cope]], who were in scientific competition with each other, went on to coin several other genera based on similarly sparse material that would later figure in the taxonomy of ''Allosaurus''. These include Marsh's ''Creosaurus''<ref name=OCM78/> and ''Labrosaurus'',<ref name=OCM79>{{cite journal |last=Marsh |first=Othniel Charles |year=1879 |title=Principal characters of American Jurassic dinosaurs. Part II |journal=American Journal of Science |series=Series 3 |volume=17 |issue=97 |pages=86–92 |doi=10.2475/ajs.s3-17.97.86 |url=https://babel.hathitrust.org/cgi/imgsrv/download/pdf?id=hvd.32044107172876;orient=0;size=100;seq=5;attachment=0 |hdl=2027/hvd.32044107172876 |s2cid=219247096 |hdl-access=free |archive-date=November 9, 2021 |access-date=August 6, 2018 |archive-url=https://web.archive.org/web/20211109005146/https://babel.hathitrust.org/cgi/imgsrv/download/pdf?id=hvd.32044107172876;orient=0;size=100;seq=5;attachment=0 |url-status=live }}</ref> as well as Cope's ''Epanterias''.<ref name=EDC78/>

In their haste, Cope and Marsh did not always follow up on their discoveries (or, more commonly, those made by their subordinates). For example, after the discovery by [[Benjamin Franklin Mudge|Benjamin Mudge]] of the type specimen of ''Allosaurus'' in Colorado, Marsh elected to concentrate work in [[Wyoming]]. When work resumed at Garden Park in [[1883 in paleontology|1883]], M. P. Felch found an almost complete ''Allosaurus'' and several partial skeletons.<ref name=DBN85/> In addition, one of Cope's collectors, H. F. Hubbell, found a specimen in the [[Como Bluff]] area of Wyoming in [[1879 in paleontology|1879]], but apparently did not mention its completeness and Cope never unpacked it. Upon unpacking it in [[1903 in paleontology|1903]] (several years after Cope had died), it was found to be one of the most complete theropod specimens then known and the skeleton, now cataloged as AMNH 5753, was put on public view in [[1908 in paleontology|1908]].<ref name=NGD95>{{cite book |last1=Norell |first1=Mark A. |last2=Gaffney, Eric S. |last3=Dingus, Lowell |title=Discovering Dinosaurs in the American Museum of Natural History |publisher=Knopf |location=New York |year=1995 |pages=[https://archive.org/details/discoveringdinos00nore_0/page/112 112–113] |isbn=978-0-679-43386-6 |url=https://archive.org/details/discoveringdinos00nore_0/page/112 }}</ref> This is the well-known mount poised over a partial ''[[Apatosaurus]]'' skeleton as if [[Scavenger|scavenging]] it, illustrated as such in a painting by [[Charles R. Knight]]. Although notable as the first free-standing mount of a theropod dinosaur and often illustrated and photographed, it has never been scientifically described.<ref name=BBetal99>{{cite journal |last=Breithaupt |first=Brent H. |year=1999 |title=AMNH 5753: The world's first free-standing theropod skeleton |journal=Journal of Vertebrate Paleontology |volume=19 |issue= |page=33A | doi = 10.1080/02724634.1999.10011202}}</ref>

The multiplicity of early names complicated later research, with the situation compounded by the terse descriptions provided by Marsh and Cope. Even at the time, authors such as [[Samuel Wendell Williston]] suggested that too many names had been coined.<ref name=SWW78>{{cite journal |last=Williston |first=Samuel Wendell |year=1878 |title=American Jurassic dinosaurs |journal=Transactions of the Kansas Academy of Science |volume=6 |pages=42–46 |doi=10.2307/3623553 |jstor=3623553 }}</ref> For example, Williston pointed out in [[1901 in paleontology|1901]] that Marsh had never been able to adequately distinguish ''Allosaurus'' from ''Creosaurus''.<ref name=SWW01>{{cite journal |last=Williston |first=Samuel Wendell |year=1901 |title=The dinosaurian genus ''Creosaurus'', Marsh |journal=American Journal of Science |series=Series 4 |volume=11 |issue=62 |pages=111–114 |doi=10.2475/ajs.s4-11.62.111 |url=https://zenodo.org/record/1450114 |bibcode=1901AmJS...11..111W |archive-date=November 9, 2021 |access-date=June 28, 2019 |archive-url=https://web.archive.org/web/20211109012757/https://zenodo.org/record/1450114 |url-status=live }}</ref> The most influential early attempt to sort out the convoluted situation was produced by [[Charles W. Gilmore]] in [[1920 in paleontology|1920]]. He came to the conclusion that the tail vertebra named ''Antrodemus'' by Leidy was indistinguishable from those of ''Allosaurus'' and that ''Antrodemus'' should be the preferred name because, as the older name, it had priority.<ref name=CWG20/> ''Antrodemus'' became the accepted name for this familiar genus for over 50 years, until [[James Henry Madsen]] published on the Cleveland-Lloyd specimens and concluded that ''Allosaurus'' should be used because ''Antrodemus'' was based on material with poor, if any, diagnostic features and locality information. For example, the [[geological formation]] that the single bone of ''Antrodemus'' came from is unknown.<ref name=JM76/> "''Antrodemus''" has been used informally for convenience when distinguishing between the skull Gilmore restored and the composite skull restored by Madsen.<ref name=DH98>{{cite journal |last=Henderson |first=Donald M. |year=1998 |title=Skull and tooth morphology as indicators of niche partitioning in sympatric Morrison Formation theropods |journal=Gaia |volume=15 |pages=219–266 |url=https://www.researchgate.net/publication/228687281}}</ref>