Editing Moropus (section)

=== Taxonomy ===
Chalicotheres are part of the order [[Perissodactyla]], which includes modern [[Equidae|equines]], [[Rhinoceros|rhinoceroses]], and [[Tapir|tapirs]], as well as extinct groups like [[Brontotheriidae|brontotheres]].<ref name="MamEv2">{{cite book |author1=Savage, RJG |url=https://archive.org/details/mammalevolutioni0000sava |title=Mammal Evolution: an illustrated guide |author2=Long, MR |publisher=Facts on File |year=1986 |isbn=0-8160-1194-X |location=New York |pages=[https://archive.org/details/mammalevolutioni0000sava/page/198 198–199] |url-access=registration}}</ref><ref name=":4">{{Cite journal |last1=Holbrook |first1=Luke T. |last2=Lucas |first2=Spencer G. |last3=Emry |first3=Robert J. |date=2004 |title=Skulls of the Eocene Perissodactyls (Mammalia) "Homogalax" and "Isectolophus" |url=https://www.jstor.org/stable/4524789 |journal=Journal of Vertebrate Paleontology |volume=24 |issue=4 |pages=951–956 |doi=10.1671/0272-4634(2004)024[0951:SOTEPM]2.0.CO;2 |issn=0272-4634 |jstor=4524789 |s2cid=86289060|url-access=subscription }}</ref> As the early evolution of perissodactyls is still unresolved, their closest relatives among other perissodactyl groups is obscure.<ref name=":4" /> They are generally placed as part of the clade [[Ancylopoda]] alongside their close relatives [[Lophiodontidae]]. Many studies considered them as closer to [[Perissodactyla|Ceratomorpha]] (which includes tapirs and rhinoceroses) than [[Equoidea]].<ref>{{Cite journal |last=Froehlich |first=David J. |date=1999 |title=Phylogenetic Systematics of Basal Perissodactyls |url=https://www.jstor.org/stable/4523976 |journal=Journal of Vertebrate Paleontology |volume=19 |issue=1 |pages=140–159 |bibcode=1999JVPal..19..140F |doi=10.1080/02724634.1999.10011129 |issn=0272-4634 |jstor=4523976|url-access=subscription }}</ref><ref>{{Citation |last=Tsoukala |first=Evangelia |title=The Fossil Record of Chalicotheres (Mammalia: Perissodactyla: Chalicotheriidae) in Greece |date=2022 |work=Fossil Vertebrates of Greece Vol. 2 |pages=501–517 |editor-last=Vlachos |editor-first=Evangelos |url=https://link.springer.com/10.1007/978-3-030-68442-6_15 |access-date=2024-08-22 |place=Cham |publisher=Springer International Publishing |language=en |doi=10.1007/978-3-030-68442-6_15 |isbn=978-3-030-68441-9|url-access=subscription }}</ref> A 2004 [[Cladistics|cladistic]] study alternatively recovered Ancylopoda as sister to all modern [[Perissodactyla|perissodactyls]] (which includes Equoidea and Ceratomorpha), with the [[Brontotheriidae|brontotheres]] [[Basal (phylogenetics)|basal]] to both.<ref>{{Cite journal |last1=Hooker |first1=J. J. |last2=Dashzeveg |first2=D. |date=2004 |title=The origin of chalicotheres (Perissodactyla, Mammalia) |journal=Palaeontology |language=en |volume=47 |issue=6 |pages=1363–1386 |bibcode=2004Palgy..47.1363H |doi=10.1111/j.0031-0239.2004.00421.x |issn=1475-4983 |s2cid=83720739 |doi-access=free}}</ref>

In their 1914 monograph on chalicotheres, Holland and Peterson listed three [[Subfamily|subfamilies]]: Moropodinae (''Ancylotherium'', ''Moropus'', and ''Nestoritherium''), Macrotheriinae (including ''[[Chalicotherium]]'', ''Circotherium'', and ''Macrotherium'') and [[Schizotheriinae]] (''[[Peratherium|Pernatherium]]'' and ''[[Schizotherium]]'').<ref name=":0" /> Macrotheriinae was subsequently synonymised with the existing [[Chalicotheriinae]]. Palaeontologist [[Arthur Smith Woodward]], in 1925, concurred with the system used by Holland and Peterson, and only altered the placements of a few genera.<ref name=":5">{{Cite journal |last1=Colbert |first1=Edwin Harris |author-link1=Edwin H. Colbert |last2=Brown |first2=Barnum |author-link2=Barnum Brown |date=1935 |title=Distributional and phylogenetic studies on Indian fossil mammals. 3, A classification of the Chalicotherioidea. |url=https://digitallibrary.amnh.org/items/7cfd1925-eb6f-449b-8bbe-60f9a8f71028 |journal=American Museum Novitates |issue=798}}</ref> [[William Diller Matthew]] instead split chalicotheres into just two subfamilies, Chalicotheriinae and [[Eomoropidae|Eomoropinae]]. The former was divided into two clades based on whether their teeth were [[Molar (tooth)|brachydont]] (short-crowned) or [[hypsodont]] (high-crowned): ''Moropus'' fell into the latter category.<ref name=":6">{{Cite journal |last=Matthew |first=William Diller |author-link=William Diller Matthew |date=1929 |title=Critical Observations Upon Siwalik Mammals |journal=Bulletin of the American Museum of Natural History |pages=516–524}}</ref> In 1935, [[Edwin H. Colbert]] retained this system, though divided Chalicotheriinae into the [[Tribe (biology)|tribes]] Chalicotheriini and Schizotheriini.<ref name=":5" /> Currently, they are both treated as tribes,<ref name="butler1965"/> and eomoropids have been removed from Chalicotheriidae entirely.<ref>{{Cite journal |last=Holbrook |first=L |date=1999 |title=The Phylogeny and Classification of Tapiromorph Perissodactyls (Mammalia) |url=https://doc.rero.ch/record/20950/files/PAL_E4153.pdf |journal=Cladistics |language=en |volume=15 |issue=3 |pages=331–350 |doi=10.1006/clad.1999.0107}}</ref><ref>{{Cite journal |last1=Missiaen |first1=Pieter |last2=Gingerich |first2=Philip D. |date=2012 |title=New Early Eocene Tapiromorph Perissodactyls from the Ghazij Formation of Pakistan, with Implications for Mammalian Biochronology in Asia |url=http://www.app.pan.pl/article/item/app20100093.html |journal=Acta Palaeontologica Polonica |language=en |volume=57 |issue=1 |pages=21–34 |doi=10.4202/app.2010.0093 |issn=0567-7920|hdl=1854/LU-3178691 |hdl-access=free }}</ref> ''Moropus'' is currently classified under Schizotheriinae.<ref>{{Cite journal |last1=Coombs |first1=Margery C. |last2=Hunt |first2=Robert M. |last3=Stepleton |first3=Ellen |last4=Albright |first4=L. Barry |last5=Fremd |first5=Theodore J. |date=2001-08-22 |title=Stratigraphy, chronology, biogeography, and taxonomy of early Miocene small chalicotheres in North America |url=http://www.tandfonline.com/doi/abs/10.1671/0272-4634%282001%29021%5B0607%3ASCBATO%5D2.0.CO%3B2 |journal=Journal of Vertebrate Paleontology |language=en |volume=21 |issue=3 |pages=607–620 |doi=10.1671/0272-4634(2001)021[0607:SCBATO]2.0.CO;2 |issn=0272-4634|url-access=subscription }}</ref>