Editing Saber-toothed predator (section)

{{Short description|Group of extinct animals}}
{{pp-semi-indef}}
{{Use American English|date = September 2019}}
[[File:Saber tooth 2.jpg|thumb|
From top and from left to right, ''[[Inostrancevia]]'', ''[[Hoplophoneus]]'', ''[[Barbourofelis]]'', ''[[Smilodon]]'', ''[[Machaeroides]]'' and ''[[Thylacosmilus]]'']]

A '''saber-tooth''' (alternatively spelled '''sabre-tooth''') is any member of various extinct groups of [[Predation|predatory]] [[Therapsid|therapsids]], predominantly [[Carnivora|carnivoran]] mammals, that are characterized by long, curved [[saber]]-shaped canine teeth which protruded from the mouth when closed.

Among the earliest animals that can be described as "sabertooths" are the [[Gorgonopsia|gorgonopsids]], a group of non-mammalian therapsids that lived during the Middle-Late [[Permian]], around 270-252 million years ago.<ref name="Kammerer2016" /> Saber-toothed mammals have been found almost worldwide from the [[Eocene]] epoch to the end of the [[Pleistocene]] epoch (42 million years ago – 11,000 years ago).<ref>{{cite web |title=PaleoBiology Database: ''Smilodon'', basic info |url=https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=41079 |access-date=2012-09-06 |publisher=Paleodb.org}}</ref><ref>{{cite web |title=PaleoBiology Database: ''Nimravidae'', basic info |url=https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=41036 |access-date=2012-09-06 |publisher=Paleodb.org}}</ref><ref>{{cite web |title=PaleoBiology Database: ''Barbourofelidae'', basic info |url=https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=41043 |access-date=2012-09-06 |publisher=Paleodb.org}}</ref>

One of the best-known genera is the [[Machairodontinae|machairodont]] or "saber-toothed cat" ''[[Smilodon]]'', the species of which, especially ''S. fatalis'', are popularly referred to as "saber-toothed tigers", although they are not closely related to [[tiger]]s (''[[Panthera]]''). Despite some similarities, not all saber-tooths are closely related to saber-toothed cats or [[Felidae|felids]] in-general. Instead, many members are classified into different [[Family (biology)|families]] of [[Feliformia]], such as [[Barbourofelidae]] and [[Nimravidae]];<ref name="Barrett e1658">{{Cite journal|last=Barrett|first=Paul Z.|date=2016-01-01|title=Taxonomic and systematic revisions to the North American Nimravidae (Mammalia, Carnivora)|journal=PeerJ|volume=4|pages=e1658|doi=10.7717/peerj.1658|pmc=4756750|pmid=26893959 |doi-access=free }}</ref> the [[Oxyaenidae|oxyaenid]] "[[creodont]]" genera ''[[Machaeroides]]'' and ''[[Apataelurus]]''; and two extinct lineages of [[metatheria]]n mammals, the [[Thylacosmilidae|thylacosmilids]] of [[Sparassodonta]], and [[Deltatheroida|deltatheroideans]], which are more closely related to [[marsupial]]s. In this regard, these saber-toothed mammals can be viewed as examples of [[convergent evolution]].<ref>{{Cite book|title=Sabertooth (Life of the Past)|last=Antón|first=Mauricio|publisher=Indiana University Press|year=2013}}</ref> This convergence is remarkable due not only to the development of elongated canines, but also a suite of other characteristics, such as a wide gape and bulky forelimbs, which is so consistent that it has been termed the "saber-tooth suite."<ref>{{Cite journal|last=Meachen-Samuels|first=Julie A.|title=Morphological convergence of the prey-killing arsenal of sabertooth predators|journal=Paleobiology|volume=38|issue=1|pages=1–14|doi=10.1666/10036.1|year=2012|s2cid=86749260}}</ref>

Of the feliform lineages, the family Nimravidae is the oldest, entering the landscape around 42 mya and becoming extinct by 7.2 mya. Barbourofelidae entered around 16.9 mya and were extinct by 9 mya. These two would have shared some habitats.