Editing Smilodon (section)

== Taxonomy ==

{{multiple image |align = left |direction = horizontal |total_width = 400
|image1 = Smilodon populator mandible collected by Lund.jpg
|alt1 =
|image2 = Smilodon populator skull in the Zoological Museum of Copenhagen.jpg
|alt2 =
|footer = ''S. populator'' mandible collected by [[Peter Wilhelm Lund|Lund]] who described the species (left) and [[canine tooth]] from Lund's collection (right) next to a later found skull, [[Natural History Museum of Denmark]]
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During the 1830s, Danish [[naturalist]] [[Peter Wilhelm Lund]] and his assistants [[collected fossils]] in the [[calcareous]] caves near the small town of [[Lagoa Santa, Minas Gerais]], Brazil. Among the thousands of fossils found, he recognized a few isolated [[cheek teeth]] as belonging to a [[hyena]], which he named ''Hyaena neogaea'' in 1839. After more material was found (including [[incisor teeth]] and foot bones), Lund concluded the fossils instead belonged to a distinct genus of felids, though transitional to the hyenas. He stated it would have matched the largest modern predators in size, and was more robust than any modern cat. Lund originally wanted to call the new genus ''[[Hyaenodon]]'', but realizing this name had recently been applied to another prehistoric predator, he instead named it ''Smilodon populator'' in 1842. He explained the [[Ancient Greek]] meaning of ''Smilodon'' as {{lang|grc|σμίλη}} ({{Lang|grc-latn|smilē}}), {{Gloss|scalpel}} or {{Gloss|two-edged knife}}, and {{Lang|grc|οδόντος}} ({{Lang|grc-latn|odóntos}}), {{Gloss|tooth}}. This has also been translated as "tooth shaped like double-edged knife". He explained the species name ''populator'' as "the destroyer", which has also been translated as "he who brings devastation". Lund based the name on the shape of the incisors, and the large [[canine teeth]] were not known until 1846. By 1846, Lund had acquired nearly every part of the skeleton (from different individuals), and more specimens were found in neighboring countries by other collectors in the following years.{{Sfn|Antón|2013|pp=3–26}}<ref>{{cite book |last=Lund |first=P. W. |year=1842 |title=Blik paa Brasiliens Dyreverden för sidste Jordomvæltning |trans-title=Look at Brazil's animal world before the last earth upheaval |language=da |publisher=Det Kongelige Danske Videnskabernes Selskabs Naturvidenskabelige og Matematiske Afhandlinger |location=Copenhagen |pages=54–57 |url={{google books|plainurl=yes|id=4MkQAAAAIAAJ}}}}</ref><ref name="Iconic">{{cite book|last1=McDonald |first1=H. Gregory |title=''Smilodon'': The Iconic Sabertooth |chapter=''Smilodon'': a short history of becoming the iconic sabertooth |date=2018 |editor-last1=Werdelin |editor-first1=L. |editor-last2=McDonald |editor-first2=H. G. |editor-last3=Shaw |editor-first3=C. A. |publisher=Johns Hopkins University Press |location=Baltimore |isbn=9781421425573 |pages=1–11 |url=https://muse.jhu.edu/book/58589}}</ref> Though some later authors used Lund's original species name ''neogaea'' instead of ''populator'', it is now considered an invalid ''[[nomen nudum]]'', as it was not accompanied with a proper [[species description|description]] and no type specimens were designated.<ref name="Status" /> Some South American specimens have been referred to other genera, subgenera, species, and [[subspecies]], such as ''Smilodontidion riggii'', ''Smilodon'' (''Prosmilodon'') ''ensenadensis'', and ''S.&nbsp;bonaeriensis'', but these are now thought to be [[Synonym (taxonomy)#Zoology|junior synonyms]] of ''S.&nbsp;populator''.{{Sfn|Antón|2013|pp=108–154}}

[[File:Smilodon fatalis holotype.jpg|thumb|1869 [[lithograph]] of the [[holotype]] molar and maxilla fragment of ''S. fatalis'']]

Fossils of ''Smilodon'' were discovered in North America from the second half of the 19th century onwards.{{Sfn|Antón|2013|pp=3–26}} In 1869, American paleontologist [[Joseph Leidy]] described a [[maxilla]] fragment with a [[molar (tooth)|molar]], which had been discovered in a petroleum bed in [[Hardin County, Texas]]. He referred the specimen to the genus ''[[Felis]]'' (which was then used for most cats, extant as well as extinct) but found it distinct enough to be part of its own [[subgenus]], as ''F.'' (''Trucifelis'') ''fatalis''.<ref>{{cite journal |last=Leidy |first=J. |year=1869 |title=The extinct mammalian fauna of Dakota and Nebraska: Including an account of some allied forms from other localities, together with a synopsis of the mammalian remains of North America |journal=Journal of the Academy of Natural Sciences of Philadelphia |doi=10.5962/bhl.title.20910 |volume=7 |pages=366–367 |url=https://www.biodiversitylibrary.org/item/60918#page/372/mode/1up|doi-access=free }}</ref> The species name means "deadly".<ref>{{cite web|title=Sabertooth |date=21 September 2011 |publisher=National Geographic |url=https://www.nationalgeographic.org/media/sabertooth/ |access-date=2021-10-13}}</ref> In an 1880 article about extinct American cats, American paleontologist [[Edward Drinker Cope]] pointed out that the ''F.&nbsp;fatalis'' molar was identical to that of ''Smilodon'', and he proposed the [[new combination]] ''S.&nbsp;fatalis''.<ref name="Cope" /> Most North American finds were scanty until excavations began in the [[La Brea Tar Pits]] in [[Los Angeles]], where hundreds of individuals of ''S.&nbsp;fatalis'' have been found since 1875.{{Sfn|Antón|2013|pp=3–26}} ''S.&nbsp;fatalis'' has junior synonyms such as ''S.&nbsp;mercerii'', ''S.&nbsp;floridanus'', and ''S.&nbsp;californicus''.{{Sfn|Antón|2013|pp=108–154}} American paleontologist Annalisa Berta considered the holotype of ''S.&nbsp;fatalis'' too incomplete to be an adequate type specimen, and the species has at times been proposed to be a junior synonym of ''S.&nbsp;populator''.<ref name="Status">{{cite journal |last=Berta |first=A. |year=1985 |title=The status of ''Smilodon'' in North and South America |journal=Contributions in Science, Natural History Museum of Los Angeles County |volume=370 |pages=1–15 |url=http://www.nhm.org/site/sites/default/files/pdf/contrib_science/CS370.pdf|archive-url=https://web.archive.org/web/20140528023417/http://www.nhm.org/site/sites/default/files/pdf/contrib_science/CS370.pdf|archive-date=28 May 2014}}</ref> Nordic paleontologists [[Björn Kurtén]] and [[Lars Werdelin]] supported the distinctness of the two species in an article published in 1990.<ref name=Kurten /> A 2018 article by the American paleontologist John P. Babiarz and colleagues concluded that ''S. californicus'', represented by the specimens from the La Brea Tar Pits, was a distinct species from ''S. fatalis'' after all and that more research is needed to clarify the taxonomy of the lineage.<ref>{{cite book |last1=Babiarz |first1=J. P. |last2=Todd Wheeler |first2=H. |last3=Knight |first3=J. L. |last4=Martin |first4=L. D. |title=''Smilodon'': The Iconic Sabertooth |editor-last1=Werdelin |editor-first1=L. |editor-last2=McDonald |editor-first2=H. G. |editor-last3=Shaw |editor-first3=C. A. |date=2018 |publisher=Johns Hopkins University Press |location=Baltimore |isbn=978-1-4214-2557-3 |pages=76–95 |chapter=''Smilodon'' from South Carolina: Implications for the taxonomy of the genus |url=https://muse.jhu.edu/chapter/2105166 |language=en}}</ref>

In his 1880 article about extinct cats, Cope also named a third species of ''Smilodon'', ''S.&nbsp;gracilis''. The species was based on a partial canine, which had been obtained in the [[Port Kennedy Bone Cave|Port Kennedy Cave]] near the [[Schuylkill River]] in Pennsylvania. Cope found the canine to be distinct from that of the other ''Smilodon'' species due to its smaller size and more compressed base.<ref name="Cope">{{cite journal |last=Cope |first=E. D. |author-link=Edward Drinker Cope |date=December 1880 |title=On the extinct cats of America |journal=The American Naturalist |jstor=2449549 |doi=10.1086/272672 |volume=14 |issue=12 |pages=833–858|doi-access=free }}</ref> Its [[Specific name (zoology)|specific name]] refers to the species' lighter build.<ref>{{cite book |last1=Kurtén |first1=B. |last2=Anderson |first2=E. |year=1980 |title=Pleistocene Mammals of North America |publisher=Columbia University Press |isbn=978-0-231-03733-4 |location=New York |pages=186–188 |url=https://archive.org/details/pleistocenemamma0000kurt/page/186/mode/1up}}</ref> This species is known from fewer and less complete remains than the other members of the genus.<ref>{{cite journal |last=Berta |first=A. |year=1987 |title=The sabercat ''Smilodon gracilis'' from Florida and a discussion of its relationships (Mammalia, Felidae, Smilodontini) |journal=Bulletin of the Florida State Museum |volume=31 |pages=1–63 |url=http://ufdc.ufl.edu/UF00095816/00001/1j}}</ref> ''S.&nbsp;gracilis'' has at times been considered part of genera such as ''[[Megantereon]]'' and ''[[Ischyrosmilus]]''.<ref>{{Cite journal |last=Churcher |first=C. S. |year=1984 |title=The status of ''Smilodontopsis'' (Brown, 1908) and ''Ischyrosmilus'' (Merriam, 1918): a taxonomic review of two genera of sabretooth cats (Felidae, Machairodontinae) |journal=Royal Ontario Museum Life Sciences Contributions |isbn=978-0-88854-305-9 |doi=10.5962/bhl.title.52222 |volume=140 |pages=[https://archive.org/details/statusofsmilodon00chur/page/14 14–34] |url=https://archive.org/details/statusofsmilodon00chur/page/14 |doi-access=free }}</ref> ''S.&nbsp;populator'', ''S.&nbsp;fatalis'' and ''S.&nbsp;gracilis'' are currently considered the only valid species of ''Smilodon'', and features used to define most of their junior synonyms have been dismissed as variation between individuals of the same species (intraspecific variation).{{Sfn|Antón|2013|pp=108–154}}<ref name="Status" /> One of the most famous of prehistoric mammals, ''Smilodon'' has often been featured in popular media and is the [[state fossil]] of California.{{Sfn|Antón|2013|pp=3–26}}

=== Evolution ===
[[File:Smilodon gracilis skull ANSP 44.1 (2).jpg|thumb|Partial skull of ''S. gracilis'', the earliest species in the [[genus]], [[Academy of Natural Sciences of Philadelphia]]]]
[[File:Smilodon californicus mount.jpg|thumb|right|''S. fatalis'' skeleton at [[National Museum of Natural History]]]]
[[File:Säbelzahnkatze, Tierpark Berlin, 500-606.jpg|thumb|right|''S. populator'' statue in [[Tierpark Berlin]] ]]
Long the most completely known [[Machairodontinae|saber-toothed cat]], ''Smilodon'' is still one of the best-known members of the group, to the point where the two concepts have been confused. The term [[Saber-toothed predator|''saber-tooth'']] itself refers to an [[ecomorph]] consisting of various groups of extinct predatory [[synapsid]]s (mammals and close relatives), which [[convergently evolved]] extremely long [[maxillary canine]]s, as well as adaptations to the skull and skeleton related to their use. This includes members of [[Gorgonopsia]], [[Thylacosmilidae]], [[Machaeroidinae]], [[Nimravidae]], [[Barbourofelidae]], and [[Machairodontinae]].{{Sfn|Antón|2013|pp=3–26}}<ref>{{cite journal |last1=Meehan |first1=T. J. |last2=Martin |first2=L. D. |year=2003 |title=Extinction and re-evolution of similar adaptive types (ecomorphs) in Cenozoic North American ungulates and carnivores reflect van der Hammen's cycles |journal=Die Naturwissenschaften |doi=10.1007/s00114-002-0392-1 |bibcode=2003NW.....90..131M|pmid=12649755 |volume=90 |issue=3 |pages=131–135 |s2cid=21117744 |url=https://www.researchgate.net/publication/10844456 }}</ref> Within the family [[Felidae]] (true cats), members of the [[subfamily]] [[Machairodontinae]] are referred to as saber-toothed cats, and this group is itself divided into three [[Tribe (biology)|tribes]]: [[Metailurini]] (false saber-tooths); [[Homotherini]] ([[scimitar]]-toothed cats); and [[Smilodontini]] ([[dirk]]-toothed cats), to which ''Smilodon'' belongs.{{Sfn|Antón|2013|pp=108–154}}

Members of Smilodontini are defined by their long slender canines with fine to no [[serration]]s, whereas Homotherini are typified by shorter, broad, and more flattened canines, with coarser serrations.{{Sfn|Antón|2013|pp=65–76}} Members of Metailurini were less specialized and had shorter, less flattened canines, and are not recognized as members of Machairodontinae by some researchers.{{Sfn|Antón|2013|pp=108–154}}

Despite the colloquial name "saber-toothed tiger", ''Smilodon'' is not closely related to the modern [[tiger]] (which belongs in the subfamily [[Pantherinae]]), or any other extant felid.<ref name="Berkeley">{{cite web |date=December 2005 |title=What Is a Sabertooth? |url=http://www.ucmp.berkeley.edu/mammal/carnivora/sabretooth.html |access-date=2012-06-12 |publisher=University of California Museum of Paleontology}}</ref> A 1992 ancient DNA analysis suggested that ''Smilodon'' should be grouped with modern cats (subfamilies [[Felinae]] and Pantherinae).<ref>{{cite journal |last1=Janczewski |first1=D. N. |last2=Yuhki |first2=N. |last3=Gilbert |first3=D. A. |last4=Jefferson |first4=G. T. |last5=O'Brien |first5=S. J. |year=1992 |title=Molecular phylogenetic inference from saber-toothed cat fossils of Rancho La Brea |journal=Proceedings of the National Academy of Sciences |volume=89 |issue=20 |pages=9769–9773 |bibcode=1992PNAS...89.9769J |doi=10.1073/pnas.89.20.9769 |pmc=50214 |pmid=1409696 |doi-access=free}}</ref> A 2005 study found that ''Smilodon'' belonged to a separate lineage.<ref name="Barnett">{{cite journal |last1=Barnett |first1=R. |last2=Barnes |first2=I. |last3=Phillips |first3=M. J. |last4=Martin |first4=L. D. |last5=Harington |first5=C. R. |last6=Leonard |first6=J. A. |last7=Cooper |first7=A. |year=2005 |title=Evolution of the extinct sabretooths and the American cheetah-like cat |journal=Current Biology |volume=15 |issue=15 |pages=R589–R590 |bibcode=2005CBio...15.R589B |doi=10.1016/j.cub.2005.07.052 |pmid=16085477 |s2cid=17665121 |doi-access=free}}</ref> A study published in 2006 confirmed this, showing that the Machairodontinae [[Speciation|diverged]] early from the ancestors of living cats and were not closely related to any living species.<ref>{{cite journal |last1=van den Hoek Ostende |first1=L. W. |last2=Morlo |first2=M. |last3=Nagel |first3=D. |year=2006 |title=Majestic killers: the sabre-toothed cats (Fossils explained 52) |journal=Geology Today |volume=22 |issue=4 |pages=150–157 |doi=10.1111/j.1365-2451.2006.00572.x |s2cid=128960196}}</ref> The ancestors of living cats and Machairodontinae estimated to have diverged around 20 million years ago.<ref name="Paijmans2017" /> The following [[cladogram]] based on fossils and DNA analysis shows the placement of ''Smilodon'' among extinct and extant felids, after Rincón and colleagues, 2011:<ref name="Rincón2011">{{cite journal |last1=Rincón |first1=A. |last2=Prevosti |first2=F. |last3=Parra |first3=G. |year=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 |bibcode=2011JVPal..31..468R |doi=10.1080/02724634.2011.550366 |jstor=25835839 |s2cid=129693331 |hdl-access=free |hdl=11336/69016}}</ref>

{{clade| style=font-size:85%; line-height:85%
|label1=[[Felidae]]
|1={{clade
 |1=''[[Proailurus]]''
 |2={{clade
  |1=''[[Pseudaelurus]]''
  |2={{clade
   |1={{clade
   |label1=[[Pantherinae]]
   |1=''[[Panthera]]'' (tigers, lions, jaguars, and leopards)[[File:Lydekker - Leopard (white background).JPG|70 px]]
   |label2=[[Felinae]]
    |2={{clade
     |1=''[[Caracal (genus)|Caracal]]''[[File:Felis caracal - 1818-1842 - Print - Iconographia Zoologica - Special Collections University of Amsterdam -(White Background).jpg|50 px]]
     |2={{clade
      |1=''[[Leopardus]]'' ([[ocelot]] and relatives)[[File:Felis pardalis - 1834 - Print - Iconographia Zoologica - Special Collections University of Amsterdam -(White Background).jpg|50px]]
      |2={{clade
       |1=''[[Felis]]'' ([[domestic cats]] and relatives)[[File:Felis chaus - 1700-1880 - Print - Iconographia Zoologica - Special Collections University of Amsterdam -(White Background).jpg|50px]]
       |2={{clade
        |1=''[[Herpailurus]]'' (jaguarundi) [[File:Lydekker - Eyra White background.jpg|45 px]]
        |2={{clade
         |1=''[[Miracinonyx]]'' [[File:Miracinonyx inexpectatus.jpg|55 px]]
         |2=''[[Puma (genus)|Puma]]'' (cougar)[[File:Felis concolor - 1818-1842 - Print - Iconographia Zoologica - Special Collections University of Amsterdam -(white background).jpg|65 px]]}} }} }} }} }} }}
  |label2=[[Machairodontinae]]
   |2={{clade
    |1=''[[Dinofelis]]'' [[File:Dinofelis15DB.jpg|70 px]]
    |2={{clade
     |1={{clade
      |1=''[[Nimravides]]''
      |2={{clade
       |1=''[[Machairodus]]'' [[File:Machairodus from Cerro de Batallones.png|50 px]]
       |2={{clade
        |1=''[[Homotherium]]''<span style="{{MirrorH}}">[[File:Homotherium_life_reconstruction.png|55 px]]</span>
        |2=''[[Xenosmilus]]''<span style="{{MirrorH}}">[[File:Xenosmilus with concealed canine.jpg|60 px]]</span> }} }} }}
     |2={{clade
      |1=''[[Paramachairodus]]''
      |2={{clade
       |1=''[[Megantereon]]''
|label2='''''Smilodon'''''
       |2={{clade
        |1='''''Smilodon gracilis'''''<span style="{{MirrorH}}">[[File:Saber Toothed Tiger (PSF).png|55 px]]</span>
        |2={{clade
         |1='''''Smilodon populator'''''[[File:Smilodon pop2 15.jpg|67 px]]
         |2='''''Smilodon fatalis'''''[[File:Smilodon fatalis Knight (white background).jpg|67 px]] }} }} }} }} }} }} }} }} }} }}

The earliest felids are known from the [[Oligocene]] of Europe, such as ''[[Proailurus]]'', and the earliest one with saber-tooth features is the [[Miocene]] genus ''[[Pseudaelurus]]''.{{Sfn|Antón|2013|pp=108–154}} The skull and mandible morphology of the earliest saber-toothed cats was similar to that of the modern [[Neofelis|clouded leopards]] (''Neofelis''). The lineage further adapted to the precision killing of large animals by developing elongated canine teeth and wider gapes, in the process sacrificing high [[Bite force quotient|bite force]].<ref>{{cite journal |last=Christiansen |first=P. |year=2008 |title=Evolution of skull and mandible shape in cats (Carnivora: Felidae) |journal=PLOS ONE |doi=10.1371/journal.pone.0002807 |pmid=18665225 |pmc=2475670 |bibcode=2008PLoSO...3.2807C |volume=3 |issue=7 |page=e2807|doi-access=free }} {{open access}}</ref> As their canines became longer, the bodies of the cats became more robust for immobilizing prey.{{Sfn|Antón|2013|pp=65–76}} In [[Autapomorphy|derived]] smilodontins and homotherins, the [[lumbar]] region of the spine and the tail became shortened, as did the hind limbs.{{Sfn|Antón|2013|pp=108–154}} Machairodonts once represented a dominant group of felids distributed across Africa, Eurasia and the North America during the Miocene and Pliocene epochs,<ref>{{Cite journal |last=Christiansen |first=Per |date=October 2010 |title=Phylogeny of the sabertoothed felids ( Carnivora: Felidae: Machairodontinae) |url=https://onlinelibrary.wiley.com/doi/10.1111/cla.12008 |journal=Cladistics |language=en |volume=29 |issue=5 |pages=543–559 |doi=10.1111/cla.12008 |pmid=34814379 |issn=0748-3007}}</ref> but progressively declined over the course of the Pleistocene,<ref>{{Cite journal |last1=Piras |first1=Paolo |last2=Silvestro |first2=Daniele |last3=Carotenuto |first3=Francesco |last4=Castiglione |first4=Silvia |last5=Kotsakis |first5=Anastassios |last6=Maiorino |first6=Leonardo |last7=Melchionna |first7=Marina |last8=Mondanaro |first8=Alessandro |last9=Sansalone |first9=Gabriele |last10=Serio |first10=Carmela |last11=Vero |first11=Veronica Anna |last12=Raia |first12=Pasquale |date=May 2018 |title=Evolution of the sabertooth mandible: A deadly ecomorphological specialization |url=https://linkinghub.elsevier.com/retrieve/pii/S0031018217310465 |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |language=en |volume=496 |pages=166–174 |doi=10.1016/j.palaeo.2018.01.034|bibcode=2018PPP...496..166P |hdl=2158/1268434 |hdl-access=free }}</ref> by the [[Late Pleistocene]], only two genera of machairodonts remained, ''Smilodon'', and the distantly related ''[[Homotherium]]'', both largely confined to the Americas. Based on [[mitochondrial DNA]] sequences [[Ancient DNA|extracted from ancient bones]], the lineages of ''Homotherium'' and ''Smilodon'' are estimated to have diverged about 18 million years ago.<ref name="Paijmans2017">{{cite journal|last1= Paijmans|first1=J. L. A.|last2= Barnett|first2= R.|last3= Gilbert|first3=M. T. P.|last4= Zepeda-Mendoza|first4=M. L.|last5= Reumer|first5=J. W. F.|last6=de Vos|first6= J.|last7= Zazula|first7= G.|last8= Nagel|first8= D.|last9= Baryshnikov|first9=G. F.|last10= Leonard|first10=J. A.|last11= Rohland|first11= N.|last12 =Westbury|first12=M. V.|last13= Barlow|first13= A.|last14= Hofreiter|first14= M.|title= Evolutionary History of Saber-Toothed Cats Based on Ancient Mitogenomics|journal= Current Biology|volume=27|issue=21|pages=3330–3336.e5|date= 2017-10-19|doi= 10.1016/j.cub.2017.09.033|pmid=29056454|doi-access= free|bibcode=2017CBio...27E3330P }}</ref>

The earliest species of ''Smilodon'' is ''S.&nbsp;gracilis'', which existed from 2.5 [[Mya (unit)|million]] to 500,000 years ago (early [[Blancan]] to [[Irvingtonian]] ages) and was the successor in North America of ''Megantereon'', from which it probably evolved. ''Megantereon'' itself had entered North America from [[Eurasia]] during the [[Pliocene]], along with ''Homotherium''. ''S.&nbsp;gracilis'' reached the northern regions of South America in the [[Early Pleistocene]] as part of the [[Great American Interchange]].<ref name="Rincón2011" />{{Sfn|Antón|2013|pp=65–76}} ''S.&nbsp;fatalis'' existed 1.6 million–10,000 years ago (late Irvingtonian to [[Rancholabrean]] ages), and replaced ''S.&nbsp;gracilis'' in North America.<ref name=Kurten /> ''S.&nbsp;populator'' existed 1 million–10,000 years ago ([[Ensenadan]] to [[Lujanian]] ages); it occurred in the eastern parts of South America.<ref>{{cite journal |last1=de Castro |first1=Mariela Cordeiro |last2=Langer |first2=Max Cardoso |year=2008 |title=New postcranial remains of ''Smilodon populator'' Lund, 1842 from South-Central Brazil |journal=Revista Brasileira de Paleontologia |doi=10.4072/rbp.2008.3.06 |volume=11 |issue=3 |pages=199–206 |doi-access=free }}</ref>