Saber-toothed cat

The terms saber-toothed cat, sabertooth, and saber-toothed tiger describe numerous species, mainly in the families Felidae (subfamily Machairodontinae), Barbourofelidae, and Nimravidae, but also including two marsupial families, that lived during various parts of the Cenozoic Era and evolved their saber-toothed characteristics entirely independently. They are most known for having maxillary canines which were, in some species, up to 20 cm long and extended down from the mouth even when the mouth was closed. Saber-toothed cats were generally more robust than today's cats and were quite bear-like in build. __TOC__

aber-tooth genera

The first saber-toothed cats appeared sometime during the Mid-Eocene, and the last genera died out thousands of years ago. The genera of saber-toothed cats, along with the regions and time periods where they have been found, is summarized here.

Saber-tooth evolutionary tree

All saber-tooth mammals lived between 33.7 million and 9,000 years ago, but the evolutionary lines that led to the various saber-tooth genera started to diverge much earlier.

The lineage that led to "Thylacosmilus" was the first to split off, in the late Cretaceous. It is a marsupial, and thus more closely related to kangaroos and opossums than the felines. The creodonts diverged next, and then the nimravids, before the blossoming of the truly feline saber-tooths.

* Class Mammalia
** Subclass Marsupialia (diverged ?, in the Cretaceous)
*** Order †Sparassodonta (an extinct group of marsupial carnivores)
**** Family †Borhyaenidae
**** Family †Thylacosmilidae
***** †"Thylacosmilus"
** Subclass Placentalia
*** Order †Creodonta (diverged ?, in the Paleocene)
**** Family †Hyaenodontidae
***** †"Hyaenodon"
***** †"Boualitomus"
***** †"Laekitherium"
***** †"Metapterodon"
***** †"Triacodon"
***** †"Parvagula"
***** †"Machaeroides"
*** Order Carnivora
**** Family †Nimravidae (diverged from the feliforms 48–55 Ma BP, in the late Eocene)
***** Subfamily †Nimravinae (Dinictis)
***** Subfamily †Hoplophoninae
**** Suborder Feliformia ('cat-like' carnivores)
***** Family †Barbourofelidae (sister taxa to Felidae)
***** Family Felidae (true cats)
****** Subfamily †Machairodontinae (diverged ?, in the ?)
******* Tribe †Homotheriini
******** †"Homotherium"
******** †"Machairodus"
******** †"Xenosmilus"
******* Tribe †Metailurini
******** †"Dinofelis"
******** †"Metailurus"
******* Tribe †Smilodontini
******** †"Megantereon"
******** †"Paramachairodus"
******** †"Smilodon"

External links

* [http://www.bluelion.org/extinct_species.htm Extinct Cats Index]
* [http://www.museum.state.il.us/exhibits/larson/smilodon.html Illinois State Museum: Saber-toothed Cats]
* [http://www.ucmp.berkeley.edu/mammal/carnivora/sabretooth.html UC Berkeley Museum of Paleontology: Saber-toothed Cats]
* [http://www.messybeast.com/cat-prehistory.htm Prehistoric cats and prehistoric cat-like creatures]