Smilodontini is an extinct tribe within the

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 until ...

or "saber-toothed cat" subfamily of 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 ...

. The tribe is also known as the "dirk-toothed cats". They were endemic to

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

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 Continent#Subcontinents, subcontinent of Eurasia ...

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 area ...

, and

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 ...

during the

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 recen ...

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

, from 10.3 mya—11,000 years ago, existing for approximately . As the name suggests, the famous genus of ''

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 ...

'' is part of this group, but there are also three other distinct genera in Smilodontini. The earliest known genus of the tribe is ''

Promegantereon ''Promegantereon'' is an extinct genus of machairodont from the Miocene of Europe. It is one of the oldest machairodont cat species in the Smilodontini and is believed to be an ancestor of ''Megantereon'' and ''Smilodon''. Description ''Promega ...

'', once thought to be a species of ''

Paramachairodus ''Paramachaerodus'' is an extinct genus of saber-tooth cat of the subfamily Machairodontinae, which was endemic to Europe and Asia during the late Miocene from 15 to 9 Ma. ''Paramacheirodus'' is one of the oldest known true saber-toothed cat ...

''. The tribe only became extinct 10,000 years ago, with the demise of ''Smilodon''. All of these are saber-toothed cats, meaning that they have long, narrow upper canines and stocky, well muscled proportions.

Description

The various members of Smilodontini are generally distinguished by their long, narrow upper canines. However, the stockiness often seen as one of the tribe's signature features varied between the different genera. ''Promegantereon'' and ''

'' for example, were likely arboreal or at the least, scansorial, given their moderately long tails, large dewclaws and smaller, slender builds. These species also had relatively small upper canines for their size, though they already showed the flat, blade-like edges that defined them as those of machairodonts. ''

Megantereon ''Megantereon'' was a genus of prehistoric machairodontine saber-toothed cat that lived in North America, Eurasia, and Africa. It may have been the ancestor of ''Smilodon''. Taxonomy Fossil fragments have been found in Africa, Eurasia, and No ...

'', a later species, was more intermediate in physiology between these earlier forms and the more

cursorial A cursorial organism is one that is adapted specifically to run. An animal can be considered cursorial if it has the ability to run fast (e.g. cheetah) or if it can keep a constant speed for a long distance (high endurance). "Cursorial" is often u ...

'' Rhizosmilodon'' and ''Smilodon'' itself, which were better built for life on ground, as well as bringing down relatively larger prey.

Classification

Phylogeny

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

Paleobiology

Like all machairodonts, smilodontins were equipped to hunt and kill prey in a manner that was seemingly quicker and more efficient than what is seen in modern cats like the

pantherinae Pantherinae is a subfamily within the family Felidae; it was named and first described by Reginald Innes Pocock in 1917 as only including the ''Panthera'' species. The Pantherinae genetically diverged from a common ancestor between and . Char ...

. Using their elongated canines, smilodontins would aim for the vital spots of the neck or belly (the exact placement of such bites is still hotly debated among experts), killing either by disembowelment of by severing major arteries such as the carotid. The enlarged carnassials would then be used to shear meat from the bones as the cat fed. In regards to feeding habits, the carnassials of ''Megantereon'' suggest that it was a loner that fed at leisurely paces in deep bushes or in trees, while ''Smilodon'' on the other end of the spectrum, lived in what was probably a highly competitive environment and in addition, seems to have been social, suggesting a need to eat as much as possible without losing a meal to scavengers.

References

{{Taxonbar, from=Q2262856 Machairodontinae Mammal tribes