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Machairodontini is an extinct tribe of large
saber-toothed cat Machairodontinae is an extinct subfamily of carnivoran mammals of the family Felidae (true cats). They were found in Asia, Africa, North America, South America, and Europe from the Miocene to the Pleistocene, living from about 16 million until ...
s of the subfamily
Machairodontinae Machairodontinae is an extinct subfamily of carnivoran mammals of the family Felidae (true cats). They were found in Asia, Africa, North America, South America, and Europe from the Miocene to the Pleistocene, living from about 16 million u ...
, that lived in
Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located enti ...
,
Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an ...
,
Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...
, and North America, during the Middle and Late
Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" ...
.


Description

Machairodont means "knife-tooth" which perfectly describes the species that make up Machairodontini. These predators are related to extant cats, the
Felinae The Felinae are a subfamily of the family Felidae. This subfamily comprises the small cats having a bony hyoid, because of which they are able to purr but not roar. Other authors have proposed an alternative definition for this subfamily: as ...
, and share a common ancestor within the
Felidae Felidae () is the family of mammals in the order Carnivora colloquially referred to as cats, and constitutes a clade. A member of this family is also called a felid (). The term "cat" refers both to felids in general and specifically to the ...
clade. Machairodontines were medium to large sized saber-toothed cats that would have reached a size rivaling today's
lion The lion (''Panthera leo'') is a large Felidae, cat of the genus ''Panthera'' native to Africa and India. It has a muscular, broad-chested body; short, rounded head; round ears; and a hairy tuft at the end of its tail. It is sexually dimorphi ...
s, which can reach weights of over . This clade is also occasionally classified as being part of the Homotherini, and includes genera such as ''
Machairodus ''Machairodus'' (from el, μαχαίρα , 'knife' and el, ὀδούς 'tooth') is a genus of large machairodontine saber-toothed cats that lived in Africa, Eurasia and North America during the late Miocene. It is the animal from which the s ...
'',
Hemimachairodus ''Hemimachairodus'' is an extinct genus of saber-tooth cat of the tribe Machairodontini and subfamily Machairodontinae. The type species, ''Hemimachairodus zwierzyckii'' was previously assigned to the genus ''Homotherium''. Fossil segments of H ...
and ''
Miomachairodus ''Miomachairodus'' is an extinct genus of large saber-toothed cats of the subfamily Machairodontinae. It is known from Miocene-age fossils in China and Turkey and persisted until the Late Miocene (early Vallesian). They were first characterized by their
scimitar A scimitar ( or ) is a single-edged sword with a convex curved blade associated with Middle Eastern, South Asian, or North African cultures. A European term, ''scimitar'' does not refer to one specific sword type, but an assortment of different ...
canines in the upper jaw. This means that the canines are shorter and coarsely serrated, with vertical flattening.Antón, Mauricio. 2013. Machairodont adaptations and affinities of the Holarctic late Miocene homotherin Machairodus(Mammalia, Carnivora, Felidae): the case of Machairodus catocopis Cope, 1887. Journal of Vertebrate Paleontology, Vol 33, Issue 5, p. 1202-1213. Although the upper canines are shorter than other more famous saber toothed cats such ''
Smilodon ''Smilodon'' is a genus of the extinct machairodont subfamily of the felids. It is one of the most famous prehistoric mammals and the best known saber-toothed cat. Although commonly known as the saber-toothed tiger, it was not closely related ...
'', they are still abnormally long in comparison to the rest of the teeth in the mandible. There is also a space separating the canines and premolars known as a diastema. The bottom portion of the jaw contains small incisors that are in a straight row with a large, lower canine. These canines are not nearly as big as the upper canines. There is a diastema between the canines and the premolars in the lower jaw as well. These prehistoric predators not only have long upper canine teeth but they also have elongated limb bones, which differ from the squatter legs of the other group of saber-toothed cats, the Smilodontini. Although not many complete skeletons of machairodontine species have been found, those specimens known illustrate the long limb bones and shorter tails. The tails are of medium length and do not reach the ground as they do with cats today.


Taxonomy

Machairodontini was named by Gill (1872) as well as de Beaumont (1964). It was assigned to
Machairodontinae Machairodontinae is an extinct subfamily of carnivoran mammals of the family Felidae (true cats). They were found in Asia, Africa, North America, South America, and Europe from the Miocene to the Pleistocene, living from about 16 million u ...
by Berta and Galiano (1983).


Classification


Phylogeny

The phylogenetic relationships of Machairodontini are shown in the following cladogram:


Geologic and geographic distribution

The earliest machairodontine is the genus
Miomachairodus ''Miomachairodus'' is an extinct genus of large saber-toothed cats of the subfamily Machairodontinae. It is known from Miocene-age fossils in China and Turkey and persisted until the Late Miocene (early Vallesian).Turkey Turkey ( tr, Türkiye ), officially the Republic of Türkiye ( tr, Türkiye Cumhuriyeti, links=no ), is a list of transcontinental countries, transcontinental country located mainly on the Anatolia, Anatolian Peninsula in Western Asia, with ...
.Qiu, Zhanxiang. 2003. Dispersals of Neogene Carnivorans between Asia and North America. Bulletin of the American Museum of Natural History, N. 279, p. 18-31. There are also species of the Machairodontini found in Africa from the
late Miocene The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene Epoch made up of two stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million years ago) to 5.333 Ma. The ...
to the early Pleistocene, in deposits such as Lothagam, Sahabi, and Langebaanweg. The Machairodontini moved East during the Vallesian (11.6-0.9 million years ago), when they entered
Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an ...
about 10 million years ago and became one of the major predators of this time.Antón, M., Salesa, M. J., Morales, J., & Turner, A. 2004. First known complete skulls of the scimitar-toothed cat ''Machairodus aphanistus'' (Felidae, Carnivora) from the Spanish Late Miocene site of Batallones-1. Journal of Vertebrate Paleontology, Vol. 24, Issue 4, p. 957-969. There were once also similarities between species found in North America and
Eurasia Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelag ...
that support an immigration event from Eurasia which took place before the late Miocene, at about the end of the early
Hemphillian The Hemphillian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 10,300,000 to 4,900,000 years BP. It is usually considered ...
(~5 million years ago). The
Old World The "Old World" is a term for Afro-Eurasia that originated in Europe , after Europeans became aware of the existence of the Americas. It is used to contrast the continents of Africa, Europe, and Asia, which were previously thought of by th ...
(Europe/Africa/Asia) species ''
Machairodus aphanistus ''Machairodus'' (from el, μαχαίρα , 'knife' and el, ὀδούς 'tooth') is a genus of large machairodontine saber-toothed cats that lived in Africa, Eurasia and North America during the late Miocene. It is the animal from which the su ...
'' and the
New World The term ''New World'' is often used to mean the majority of Earth's Western Hemisphere, specifically the Americas."America." ''The Oxford Companion to the English Language'' (). McArthur, Tom, ed., 1992. New York: Oxford University Press, p. ...
(North and South America) species ''Machairodus catocopis'' (now know to belong to the genus ''Nimravides'') were once though to have been very closely related, suggesting that there was a migration and that these saber-toothed cats did radiate from Eurasia into North America. This made sense based on evolutionary similarities between North American and Eurasian species as well as the immigration of other species between these two continents at this time in Earth's history. However, this was disproven with discoveries that the Homotherini were not descended from the Machairodontini and that several species of Machairodontine, such as ''
Nimravides catacopsis ''Nimravides'' is a genus of extinct saber-toothed cats that lived in North America during the Late Miocene, between 10.3 and 5.332 Ma. Despite its scientific name, ''Nimravides'' does not belong to the Nimravidae, but is a true cat, belonging ...
'', Homotherium and Amphimachairodus were revealed to be Homotherines.


Evolutionary Relationships

Previous analysis of the saber-toothed cats used Linnaean classification based the morphology of the upper canines, which suggested that there were four tribes within the subfamily of
Machairodontinae Machairodontinae is an extinct subfamily of carnivoran mammals of the family Felidae (true cats). They were found in Asia, Africa, North America, South America, and Europe from the Miocene to the Pleistocene, living from about 16 million u ...
. These tribes include Machairodontini, Homotherini, Smildontini, and Matailurini seen in the cladogram of Machairodontinae. Then upon finding further fossils, Machairodontini was assigned to the Homotherini tribe. The Homotherini includes species such as ''
Machairodus ''Machairodus'' (from el, μαχαίρα , 'knife' and el, ὀδούς 'tooth') is a genus of large machairodontine saber-toothed cats that lived in Africa, Eurasia and North America during the late Miocene. It is the animal from which the s ...
'', ''(M. aphanistus'' and ''M. giganteus''). These species are characterized by their scimitar teeth that make up the large upper canines. The Smildontini tribe includes species such as '' Paramachairodus'', '' Megantereon'', and
Smilodon ''Smilodon'' is a genus of the extinct machairodont subfamily of the felids. It is one of the most famous prehistoric mammals and the best known saber-toothed cat. Although commonly known as the saber-toothed tiger, it was not closely related ...
. These species have been characterized based on their longer, dagger-like teeth. The other tribe Matailurini includes species such as ''Matailurus'' and '' Dinofelis''. These have been classified by having teeth different than the previous two clades, the long serrated teeth and the long, dagger-like teeth. Unfortunately, there are few postcranial skeletons of saber-toothed cats preserved, so available phylogenetic characters are largely cranial. New research published in 2013 took a different approach to elucidating the evolutionary relationships of saber-toothed cats. This approach used
cladistic Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups (" clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived ch ...
phylogeny A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological spe ...
instead of the previous Linnaean classification. The results concluded the original four tribes could not be recovered by parsimony analysis because many of the
synapomorphies In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to hav ...
of the saber toothed cats are based on other bones that the prominent, upper canines. Workers now recognize a clade for true saber toothed cats called Eumachairodontia that includes species from all of the previously proposed tribes: '' Megantereon'', ''
Smilodon ''Smilodon'' is a genus of the extinct machairodont subfamily of the felids. It is one of the most famous prehistoric mammals and the best known saber-toothed cat. Although commonly known as the saber-toothed tiger, it was not closely related ...
'', '' Amphimachairodus'', '' Homotherium'' and '' Xenosmilus''. The
synapomorphy In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to hav ...
for the "true saber-toothed" clade Eumachairodontia is the hypertrophied, greatly flattened upper canines. The true machairodontines have a synapomorphy of flattened, small, lower canines and other bone variations such as the small upper first molar compared to basal, pre-saber toothed cats large, transversely situated upper first molar and large upper third premolar parastyle.


Morphology and Behavior

The enlarged canines of these species were not only a unique morphological trait but also were used as a specialized hunting tool. It is proposed that the effective use of the specialized canines is the canine shear-bite. This is a model that shows how the teeth would bite the prey's neck or other convex area of the body, and use the upper jaw as an anchor to pull the teeth down through the skin and create large puncture wounds for blood loss and possibly tear a significant flesh wound.Piras, P., Malorino, L., Teresi, L., Meloro, C., Lucci, F., Kotsakis, T., & Raia, P. 2013. Bite of the cats: relationships between functional integration and mechanical performance as revealed by mandible geometry. Systematic Biology, Vol. 62, Issue 6., p. 878-900. The shearing bite as mentioned above would cause less tooth breakage when used in fast pursuit. Some species within the Machairodontini show strong
sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most an ...
, such as M. aphanistus, but other machairodonts, such as the smilodontin ''Paramachairodus'', display very slight
sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most an ...
. The canines of the males seem to be larger than the female canines. This could be due to mate competition for females. The varied dimorphism does suggest that different species had different forms of lifestyles as how today's modern cats live.


See also

*
Big cat The term "big cat" is typically used to refer to any of the five living members of the genus '' Panthera'', namely the tiger, lion, jaguar, leopard, and snow leopard. Despite enormous differences in size, various cat species are quite simil ...


References

{{Taxonbar, from=Q6723386 Machairodontinae Mammal tribes Miocene carnivorans Pliocene carnivorans Pleistocene carnivorans Miocene first appearances Pleistocene extinctions