Editing Homotherium (section)

==Research history and taxonomy==
=== Eurasia ===
The first fossils of ''Homotherium'' were scientifically described in 1846 by [[Richard Owen]] as the species ''Machairodus latidens,''<ref>{{Cite book|last=Owen|first=Richard|title=A History of British Mammals and Birds|date=1846}}</ref> based on Pleistocene aged canine teeth found in [[Kents Cavern|Kent’s Cavern]] in [[Devon]], southwestern England by the Reverend [[John MacEnery]] in 1826.<ref name="barnett 2014">{{Cite journal |last=Barnett |first=Ross |date=January 2014 |title=An inventory of British remains of ''Homotherium'' (''Mammalia'', ''Carnivora'', ''Felidae''), with special reference to the material from ''Kent's Cavern'' |journal=[[Geobios]] |volume=47 |issue=1–2 |pages=19–29 |doi=10.1016/j.geobios.2013.12.004|bibcode=2014Geobi..47...19B }}</ref> The name ''Homotherium'' ([[Ancient Greek language|Greek]]: {{lang|grc|ὁμός}} ({{transliteration|grc|homos}}, 'same') and {{lang|grc|θηρίον}} ({{transliteration|grc|therion}}, 'beast')) was proposed by Emilio Fabrini in 1890 during a review of machairodont material from the Late Pliocene-Early Pleistocene of [[Tuscany]], Italy, without further explanation, for a new subgenus of ''[[Machairodus]]'', whose main distinguishing feature was the presence of a large [[diastema]] (gap) between the two lower (inferior) premolars. He further described two species in this new subgenus: ''Machairodus (Meganthereon) crenatidens'' and ''Machairodus (Meganthereon) nestianus,'' both from Tuscan remains.<ref>{{cite journal|last1=Fabrini|first1=E.|year=1890|title=I Machairodus (Meganthereon) del Val d'Arno superiore|url=https://www.biodiversitylibrary.org/item/226998#page/201/mode/1up|journal=Bollettino Comitato Geologico d'Italia|language=it|volume=21|pages=121–144, 161–177}}</ref> The genus name itself was rarely used in the scientific literature until the late 1940s.<ref name="antón etal 2014" /> In 1918, the species ''Homotherium moravicum'' was described by Josef Woldřich based on remains found in what is now the Czech Republic.<ref>{{Cite journal |last=Woldřich |first=J. |date=1916 |title=První nálezy Machaerodů v jeskynním diluviu moravském a dolnorakouském |trans-title=The first finds of Machaerods in the Moravian and Lower Austrian cave diluvium |journal=Rozpravy České akademie cís. Fr. Josefa pro vědy, slovesnost a umění, třída II |language=cs |volume=25 |issue=12 |pages=1–8}}</ref> In 1936, [[Teilhard de Chardin]] described the new species ''Homotherium ultimus'' based on fossils from the Middle Pleistocene-aged [[Zhoukoudian Peking Man Site|Zhoukoudian cave complex]] near Beijing in northern China.<ref>{{Cite journal|author=P. Teilhard de Chardin |title=Fossil mammals from Locality 9 of Choukoutien |journal=Palaeontol. Sin. Ser. C |volume=7 |date=1936 |pages=1–61}}</ref> Remains from the late Early Pleistocene-early Middle Pleistocene of [[Java]] in Indonesia have also been attributed to this species (as ''Homotherium ultimum'').<ref name="Volmer-2016">{{Cite journal |last1=Volmer |first1=Rebekka |last2=Hertler |first2=Christine |last3=van der Geer |first3=Alexandra |date=January 2016 |title=Niche overlap and competition potential among tigers (Panthera tigris), sabertoothed cats (Homotherium ultimum, Hemimachairodus zwierzyckii) and Merriam's Dog (Megacyon merriami) in the Pleistocene of Java |url=https://linkinghub.elsevier.com/retrieve/pii/S003101821500601X |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |language=en |volume=441 |pages=901–911 |doi=10.1016/j.palaeo.2015.10.039|bibcode=2016PPP...441..901V |hdl=10795/3286 |hdl-access=free }}</ref> In 1972, a species ''Homotherium davitashvili'' (also spelled ''davitasvilii<ref name="antón etal 2014" />'') was described based on fragmentary material found at the late Pliocene Kvabebi locality in Georgia.<ref>{{Cite journal|author=A.K. Vekua |title=Kvabebskaya Fauna Akchagyl'skikh pozvonochnykh |trans-title=The Kvabebi Fauna of Akchagylian Vertebrates |journal=Nauka|date=1972}}</ref><ref name="antón etal 2014" /> Other material from Odessa in Ukraine was tentatively assigned to this species in 2004.<ref>{{Cite journal |last=Sotnikova |first=M. V. |date=2004 |title=New data on the Pliocene carnivore fauna of Odessa Catacombs |journal=Problems of Stratigraphy of the Phanerozoic of Ukraine. Institute of Geological Sciences, Kiev |pages=199–202}}</ref> In 1986, the species ''Homotherium darvasicum'' was described by Scharif Scharapov based on material from Kuruksay, [[Tajikistan]].<ref>{{Cite journal |last=Scharapov |first=S. |date=1986 |title=Kuruksajskij kompleks pozdnepliocenovych mlekopitajushchikh Afgano-Tadshikskoj depressii |trans-title=The Kuruksai complex of late Pliocene milk-bearing mammals of the Afgano-Tadshik depression |journal=Duanbe (Donis) |language=sl |volume=272}}</ref> In 1989, another species ''Homotherium tielhardipiveteaui'' was named by Scharapov based on fossils also found in Tajikistan.<ref>{{Cite journal |last=Scharapov |first=S. |date=1989 |title=On a new species of the saber-toothed cat from the Late Eopleistocene of the Afgano-Tadjik depression and the evolution of the genus Homotherium Fabrini, 1890 |journal=Paleontological Journal, Moscow |volume=3 |pages=73–83}}</ref> In 1996, ''Homotherium hengduanshanense'' was described based on fossils from the [[Hengduan Mountains]] of southwestern China.<ref>{{Cite book |title=Cenozoic mammals and environment of Hengduan Mountains Region |date=1996 |publisher=China Ocean Press |isbn=978-7-5027-4157-0 |editor-last=Guanfu |editor-first=Zong |location=Beijing |display-authors=etal}}</ref> Indeterminate remains of ''Homotherium'' have been reported from the [[Siwalik Hills]] of the northern Indian subcontinent, of Early - early Middle Pleistocene age.''<ref>{{Cite journal |last=Stimpson |first=Christopher M. |date=May 2024 |title=Siwalik sabrecats: review and revised diagnosis of Megantereon fossils from the foothills of the Himalaya |journal=Royal Society Open Science |language=en |volume=11 |issue=5 |bibcode=2024RSOS...1131788S |doi=10.1098/rsos.231788 |issn=2054-5703 |pmc=11076117 |pmid=38720790}}</ref>''

In a 1954 publication, Jean Viret proposed that ''Homotherium crenatidens'' was the applicable species name for much of the ''Homotherium'' material in the Late Pliocene-Early Pleistocene of Europe. While Ficcarelli in 1979 regarded ''H. crenatidens'' and ''H. latidens'' as distinct species, this was disputed by Alan Turner in a 1999 publication, who considered that the proposed morphological differences separating the two species were invalid and the two species were not distinct.<ref name="antón etal 2014" />

A 2014 review recognised only one species of ''Homotherium'' in Eurasia during the Late Pliocene-Pleistocene, ''Homotherium latidens.'' Other named ''Homotherium'' species from this time period, including ''H. crenatidens'', were found not to be distinct. Across time and space, the remains of ''H. latidens'' display considerable morphological variability, though there does not appear to be any clear pattern in this variation temporally or geographically (with the exception of the presence of "pocketing" of the margin of the masseteric [[Fossa (anatomy)|fossa]] of the mandible appearing in Middle and Late Pleistocene ''H. latidens'', but not earlier ones), with the morphological variation of the entire span of ''Homotherium'' in Eurasia from the Late Pliocene to the Late Pleistocene being similar to the variation found at the large sample for individuals from the Incarcal locality from the Early Pleistocene of Spain, supporting a single valid species. Some older material from the Pliocene of Eastern Europe (such as that from the [[Odesa catacombs|Odesa Catacombs]] in Ukraine) was tenatively considered to belong to a separate species.<ref name="antón etal 2014" /> Some authors have continued to recognise ''Homotherium crenatidens'' as a valid, pan-Eurasian species chronologically earlier than ''H. latidens'' (with these authors suggesting that ''H. crenatidens'' spans the Late Pliocene-Early Pleistocene, while ''H. latidens'' spans the Middle-Late Pleistocene).<ref>{{Cite journal |last1=Jiangzuo |first1=Qigao |last2=Zhao |first2=Hailong |last3=Chen |first3=Xi |date=2022-07-12 |title=The first complete cranium of Homotherium (Machairodontinae, Felidae) from the Nihewan Basin (northern China) |url=https://anatomypubs.onlinelibrary.wiley.com/doi/10.1002/ar.25029 |journal=The Anatomical Record |language=en |doi=10.1002/ar.25029 |pmid=35819068 |issn=1932-8486|url-access=subscription }}</ref>

=== Africa ===
In 1947/48, [[Camille Arambourg]] described the species ''Homotherium ethiopicum'' from remains found in the Omo locality in Ethiopia.<ref>Arambourg, C., 1948. Mission Scientifique de l’Omo 1932–1933. T.1: GéologieAnthropologie. Fasc. 3. Contribution à l’étude géologique et Paléontologique du bassin du lac Rodolphe et de la basse vallée de l’Omo. Deuxième partie: paléontologie. Editions du Muséum, Paris, pp. 231–562.</ref> This publication helped popularise the genus ''Homotherium'', which was little used prior.<ref name="antón etal 2014" /> This species has been later regarded as a ''[[nomen dubium]]'', with the type specimen, a lower jaw, possibly actually belonging to ''[[Dinofelis]]'' (another machairodontine) instead.<ref name="Geraads-2015" />

In 1972 the species ''Homotherium problematicum'' (originally ''Megantereon problematicus'') was named based on fragmentary material from the [[Makapansgat]] locality in South Africa, of late Pliocene-Early Pleistocene age.<ref>{{Cite journal|last=Collings |first= G.E.|title=A new species of machairodont from Makapansgat |journal=Palaeont. Afr. |volume=14 |date=1972 |pages=87–92 |hdl=10539/16028}}</ref><ref>{{Citation |last1=Reed |first1=Kaye E. |title=Geology, Fauna, and Paleoenvironmental Reconstructions of the Makapansgat Limeworks Australopithecus africanus -Bearing Paleo-Cave |date=2022-06-09 |work=African Paleoecology and Human Evolution |pages=66–81 |editor-last=Reynolds |editor-first=Sally C. |url=https://www.cambridge.org/core/product/identifier/9781139696470%23CN-bp-7/type/book_part |access-date=2024-11-15 |edition=1 |publisher=Cambridge University Press |doi=10.1017/9781139696470.007 |isbn=978-1-139-69647-0 |last2=Kuykendall |first2=Kevin L. |last3=Herries |first3=Andy I.R. |last4=Hopley |first4=Philip J. |last5=Sponheimer |first5=Matt |last6=Werdelin |first6=Lars |editor2-last=Bobe |editor2-first=René|url-access=subscription }}</ref> ''Homotherium hadarensis'' was described in 1988, based on remains found in the Pliocene aged [[Hadar Formation]] of the Afar region of Ethiopia.<ref>{{Cite journal|author1=G. Petter |author2=F.C. Howell |title=Nouveau felidé machairodonte (Mammalia, Carnivora) de la faune pliocène de l'Afar (Ethiopie) Homotherium hadarensis n. sp |journal=C. R. Acad. Sci. Paris |volume=306 |date=1988 |pages=731–738}}</ref> In 2015, further material from the Hadar Formation was tentatively referred to ''H. hadarensis''.<ref name="Geraads-2015">{{Cite journal|doi=10.1016/j.jafrearsci.2015.03.020 |title=Pliocene Carnivora (Mammalia) from the Hadar Formation at Dikika, Lower Awash Valley, Ethiopia |date=2015 |last1=Geraads |first1=Denis |last2=Alemseged |first2=Zeresenay |last3=Bobe |first3=René |last4=Reed |first4=Denné |journal=Journal of African Earth Sciences |volume=107 |pages=28–35 |bibcode=2015JAfES.107...28G }}</ref> A third species, ''Homotherium africanum'' (originally ''Machairodus africanus''), has also been included based on remains found in Aïn Brimba, in Tunisia, North Africa,<ref>{{Cite journal|last=Arambourg |first=C. |date=1970 |title=Les vértébres du Pléistocène de l'Afrique du Nord |journal=Archives du Muséum national d'Histoire naturelle |volume=10 |pages=1–127}}</ref><ref>{{Cite journal|last1=Petter |first1=G. |last2=Howell |first2=F.C. |date=1987 |title=''Machairodus africanus'' Arambourg, 1970 (Carnivora, Mammalia) du Villafranchien d'Aïn Brimba, Tunisie |journal=Bulletin du Muséum National d'Histoire Naturelle, Paris, 4Eme SEr., C, 9 |volume=4 |pages=97–119 |url=https://pascal-francis.inist.fr/vibad/index.php?action=getRecordDetail&idt=8313058}}</ref><ref>{{Cite journal|doi=10.1016/j.jhevol.2017.05.001 |title=A contextual review of the Carnivora of Kanapoi |date=2020 |last1=Werdelin |first1=Lars |last2=Lewis |first2=Margaret E. |journal=Journal of Human Evolution |volume=140 |pmid=28625408 |bibcode=2020JHumE.14002334W |s2cid=23285088 |url=http://urn.kb.se/resolve?urn=urn:nbn:se:nrm:diva-2412 }}</ref> dating to the early-middle Pliocene.<ref name="Geraads-2008">{{Cite journal |last=Geraads |first=Denis |year=2008 |title=Plio-Pleistocene Carnivora of northwestern Africa: A short review |url=http://cr-palevol.fr/7/66 |journal=Comptes Rendus Palevol |language=en |volume=7 |issue=8 |pages=591–599 |doi=10.1016/j.crpv.2008.09.008|bibcode=2008CRPal...7..591G }}</ref> In 1990, Alan Turner challenged the validity of ''H. problematicum'' and ''H. hadarensis'', and later authors have generally refrained from referring African ''Homotherium'' fossils to any specific species due to their largely fragmentary nature.<ref name="antón etal 2014" /> In 2021, indeterminate remains of ''Homotherium'' were reported from the Tobène locality of [[Senegal]] in West Africa, dating to the Early Pliocene.<ref name="lihoreau etal 2021" /> Indeterminate remains of ''Homotherium'' have also been reported from the Ahl al Oughlam locality in Morocco, dating to the Late Pliocene.<ref name="Geraads-2008" />

=== Americas ===
In 1905, Merriam described a new species ''Machaerodus ischyrus''.<ref>{{Cite journal|last1=Merriam |first1=J. C. |date=1905 |title=A new saber-tooth from California |journal=Univ. Calif. Publ. B Geol. |volume=4 |pages=171–175}}</ref> Subsequently, in 1918, Merriam reassigned it to a new genus ''Ischyrosmilus'' along with the new species ''Ischyrosmilus idahoensis''.<ref>{{Cite journal|last1=Merriam |first1=J. C. |date=1918 |title=New mammalia from the Idaho formation |journal=Univ. Calif. Publ. Bull. Dept. Geol. |volume=10 |pages=523–530}}</ref> The genus ''Dinobastis'' was originally named by [[Edward Drinker Cope|Cope]] in 1893, with the type species ''Dinobastis serus''.<ref>{{Cite journal|last=Cope |first=E.D. |title=A new Pleistocene sabre-tooth |journal= The American Naturalist |volume=27 |date=1893 |pages=896–897}}</ref> In 1965, the species ''Ischyrosmilus johnstoni'' was described. In the same paper, it was noted that a comparative study of both ''Ischyrosmilus'' and ''Homotherium'' might conclude them as synonyms.<ref>{{Cite journal|last1=Mawby |first1=John E. |date=1965 |title=Machairodonts from the Late Cenozoic of the Panhandle of Texas |journal=Journal of Mammalogy |volume=46 |issue=4 |pages=573–587 |doi=10.2307/1377928 |jstor=1377928}}</ref>
[[File:Homotherium venezuelensis9.JPG|thumb|Skeleton of the South American species ''"Homotherium" venezuelensis,'' which recent authors have suggested may be better placed in ''[[Xenosmilus]]'']]
In 1966, Churcher deemed ''Dinobastis'' as a junior synonym of ''Homotherium'', and recombined ''D. serus'' as ''Homotherium serum.''<ref>{{Cite journal|last=Churcher |first=C. S. |date=1966 |title=The affinities of Dinobastis serus Cope 1893 |journal=Quaternaria |issue=8 |pages=263–275}}</ref> In 1970, a new species ''Ischyrosmilus crusafonti'' was described from the early Pleistocene of Nebraska.<ref>{{Cite journal|url=https://digitalcommons.unl.edu/museumbulletin/102 |title=Machairodont Cats from the Early Pleistocene Broadwater and Lisco Local Faunas |journal=Bulletin of the University of Nebraska State Museum |date=November 1970 |last1=Schultz |first1=C. |last2=Martin |first2=Larry }}</ref> In 1988, after some debate, the genus ''Ischyrosmilus'' was declared a junior synonym of ''Homotherium'' and all four species were reassigned to that genus as ''H. ischyrus'', ''H. idahoensis'', and ''H. johnstoni''. The same paper also proposed keeping ''Dinobastis serus'' separate from ''Homotherium''.<ref>{{Cite journal|last1=Martin |first1=Larry D. |last2=Schultz |first2=C. B. |last3=Schultz |first3=M. R. |title=Saber-Toothed Cats from the Plio-Pleistocene of Nebraska |date=1988 |journal=Transactions of the Nebraska Academy of Sciences and Affiliated Societies |volume=186 |url=https://digitalcommons.unl.edu/tnas/186}}</ref>  Up to five species have been recognised from North America: ''H. idahoensis'', ''H. crusafonti'', ''H. ischyrus'', ''H. johnstoni'', and ''H. serum,''<ref>{{Cite book|author1=L.D. Martin |author2=V.L. Naples |author3=J.P. Babiarz |chapter=Revision of the new World Homotheriini |title=The Other Saber-tooths: Scimitar-tooth Cats of the Western Hemisphere |publisher=Johns Hopkins University Press |location=Baltimore |date=2011 |pages=185–194}}</ref> while other authors suggest that there are only two species, with older [[Blancan]] (Pliocene-Early Pleistocene) specimens assigned to the species ''H. ischyrus'', while the younger ones (mostly Late Pleistocene in age) are assigned to the species ''H. serum''. ''H. serum'' is morphologically similar to the Eurasian ''H. latidens'', which may suggest that they share a close common origin, with ''H. serum'' possibly originating from a migration of ''H. latidens'' into North America rather than from earlier North American ''Homotherium''.<ref name="antón etal 2014" /> Some authors have considered ''H. serum'' to be a [[junior synonym]] of ''H. latidens''.<ref>{{Cite journal |last1=Rodrigues-Oliveira |first1=Igor Henrique |last2=Batista da Silva |first2=Iuri |last3=Rocha |first3=Renan Rodrigues |last4=Soares |first4=Rafael Augusto Silva |last5=Menegidio |first5=Fabiano Bezerra |last6=Garcia |first6=Caroline |last7=Pasa |first7=Rubens |last8=Kavalco |first8=Karine Frehner |date=2024-12-07 |title=When paleontology meets genomics: complete mitochondrial genomes of two saber-toothed cats' species (Felidae: Machairodontinae) |url=https://www.tandfonline.com/doi/full/10.1080/24701394.2024.2439433 |journal=Mitochondrial DNA Part A |language=en |pages=1–9 |doi=10.1080/24701394.2024.2439433 |pmid=39644159 |issn=2470-1394}}</ref>

In 2005, a new species ''Homotherium venezuelensis'' was described based on fossils from the Pleistocene of Venezuela.<ref>{{Cite journal |last1=Rincón |first1=Ascanio D. |last2=Prevosti |first2=Francisco J. |last3=Parra |first3=Gilberto E. |date=2011 |title=New Saber-Toothed Cat Records (Felidae: Machairodontinae) for the Pleistocene of Venezuela, and the Great American Biotic Interchange |journal=Journal of Vertebrate Paleontology |volume=31 |issue=2 |pages=468–478 |doi=10.1080/02724634.2011.550366 |jstor=25835839 |bibcode=2011JVPal..31..468R |s2cid=129693331|hdl=11336/69016 |hdl-access=free }}</ref> In 2022 and 2023, Jiangzuo et al. proposed that ''Homotherium venezuelensis'' be reassigned to the genus ''[[Xenosmilus]]'' (a genus originally described for Early Pleistocene aged fossils found in Florida)<ref name="jiangzuo etal 2022">{{Cite journal |last1=Jiangzuo |first1=Qigao |last2=Werdelin |first2=Lars |last3=Sun |first3=Yuanlin |date=May 2022 |title=A dwarf sabertooth cat (''Felidae'': ''Machairodontinae'') from Shanxi, China, and the phylogeny of the sabertooth tribe ''Machairodontini'' |journal=Quaternary Science Reviews |language=en |volume=284 |at=Article 107517 |bibcode=2022QSRv..28407517J |doi=10.1016/j.quascirev.2022.107517}}</ref><ref name="Jiangzuo-2023">{{Cite journal |last1=Jiangzuo |first1=Qigao |last2=Werdelin |first2=Lars |last3=Sanisidro |first3=Oscar |last4=Yang |first4=Rong |last5=Fu |first5=Jiao |last6=Li |first6=Shijie |last7=Wang |first7=Shiqi |last8=Deng |first8=Tao |date=2023-04-26 |title=Origin of adaptations to open environments and social behaviour in sabretoothed cats from the northeastern border of the Tibetan Plateau |journal=Proceedings of the Royal Society B: Biological Sciences |language=en |volume=290 |issue=1997 |doi=10.1098/rspb.2023.0019 |issn=0962-8452 |pmc=10113030 |pmid=37072045}}</ref> which was endorsed by another group of authors in 2024.<ref>{{Cite journal |last1=Manzuetti |first1=Aldo |last2=Jones |first2=Washington |last3=Rinderknecht |first3=Andrés |last4=Ubilla |first4=Martín |last5=Perea |first5=Daniel |date=December 2024 |title=Body mass of a large-sized Homotheriini (Felidae, Machairodontinae) from the Late Pliocene-Middle Pleistocene in Southern Uruguay: Paleoecological implications |journal=[[Journal of South American Earth Sciences]] |volume=149 |at=Article 105231 |doi=10.1016/j.jsames.2024.105231|bibcode=2024JSAES.14905231M }}</ref> The 2022 and 2023 studies found that ''Xenosmilus'' was nested within ''Homotherium'' as traditionally defined, making ''Homotherium'' without including the species in ''Xenosmilus'' [[paraphyletic]].<ref name="jiangzuo etal 2022" /><ref name="Jiangzuo-2023" />