Saber-toothed predator

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 predatory therapsids, predominantly carnivoran mammals, that are characterized by long, curved saber-shaped canine teeth which protruded from the mouth when closed. 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).[1][2][3]

One of the best-known genera is the 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 tigers (Panthera). Despite some similarities, not all saber-tooths are closely related to saber-toothed cats or felids in-general. Instead, many members are classified into different families of Feliformia, such as Barbourofelidae and Nimravidae;[4] the oxyaenid "creodont" genera Machaeroides and Apataelurus; and two extinct lineages of metatherian mammals, the thylacosmilids of Sparassodonta, and deltatheroideans, which are more closely related to marsupials. In this regard, these saber-toothed mammals can be viewed as examples of convergent evolution.[5] 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."[6]

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.

  1. ^ "PaleoBiology Database: Smilodon, basic info". Paleodb.org. Retrieved 2012-09-06.
  2. ^ "PaleoBiology Database: Nimravidae, basic info". Paleodb.org. Retrieved 2012-09-06.
  3. ^ "PaleoBiology Database: Barbourofelidae, basic info". Paleodb.org. Retrieved 2012-09-06.
  4. ^ Barrett, Paul Z. (2016-01-01). "Taxonomic and systematic revisions to the North American Nimravidae (Mammalia, Carnivora)". PeerJ. 4: e1658. doi:10.7717/peerj.1658. PMC 4756750. PMID 26893959.
  5. ^ Antón, Mauricio (2013). Sabertooth (Life of the Past). Indiana University Press.
  6. ^ Meachen-Samuels, Julie A. (2012). "Morphological convergence of the prey-killing arsenal of sabertooth predators". Paleobiology. 38 (1): 1–14. doi:10.1666/10036.1. S2CID 86749260.