Saber-toothed predator

File:Saber-toothcat.jpg

The fossilized skeleton of a sabre-toothed cat

The terms saber-toothed cat and saber-toothed tiger describe numerous species, mainly in the families Felidae, Hyaenodontidae, and Nimravidae, but also including two marsupial families, that lived during various parts of the Cenozoic and evolved their saber-toothed characteristics entirely independently. The saber-tooth morphology is an excellent example of convergent evolution as it occurred repeatedly and independently in at least four distinct mammalian groups. They are most known for having teeth which were in some species up to 20 cm long, and extended down from the mouth even when closed.

Saber-tooth genera

Saber-toothed cats became extinct 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:

Genus Name	Number of Species	Times	Regions
Smilodon	6	2.5 MYA to 8,000 YA	North America
Hoplophoneus	5	33.7 MYA to 23.8 MYA	North and South America
Eusmilis	3	30.5 MYA to 28 MYA	Europe, North America, South America
Dinictis	4	40 MYA to 25 MYA	North America
Dinaelurus	1	?	North America
Dinailurictis	1	?	?
Eofelis	1	?	?
Nimravidus (Nimravides)	2	?	?
Nimravus (Nimravinus)	6	33.5 MYA to 20 MYA	Europe and North America
Nimraviscus	1	?	?
Pogonodon	2	15 MYA to 6 MYA	Europe and North America
Quercylurus	1	?	?
Archaelurus	1	?	?
Aelurogale (Ailurictis)	1	?	?
Ictidailurus	1	?	?
Albanosmilus	3	18 MYA to 3 MYA	Africa and Eurasia
Afrosmilus	1	25 MYA to 10 MYA	Africa
Barbourofelis	7	15 MYA to 3 MYA	Africa and Eurasia
Ginsburgsmilus	1	23 MYA to 10 MYA	Africa
Prosansanosmilus	2	18 MYA to 5 MYA	Africa and Eurasia
Sansanosmilus	3	12 MYA to 3 MYA	Africa and Eurasia
Syrtosmilus	1	23 MYA to 8 MYA	Africa
Vampyrictis	1	15 MYA to 3 MYA	Africa and Eurasia
Vishnusmilus	1	?	?
Homotherium	10	3 MYA to 10,000 YA	Europe and Asia
Thylacosmilus (marsupial)	2	10 MYA to 1.8 MYA	South America
Metailurus	9	15 MYA to 8 MYA	Eurasia
Adelphailurus	1	23 MYA to 5 MYA	Kansas (North America)
Paramachairodus	3	20-15 MYA to 9 MYA	Europe
Machairodus (Ancestral to Homotherium)	18	15 MYA to 2 MYA	Africa, Europe, Asia, and North America
Megantereon	8	3 MYA to 9,000 YA	Africa, Eurasia, and North America
Dinofelis	6	5 MYA to 1.5 MYA	Africa, Eurasia, North America
Therailurus	1	5 MYA to 2 MYA	Africa, Eurasia, North America
Pontosmilus	4	20 MYA to 9 MYA	Eurasia
Xenosmilus (1 specimen)	1	1.7 MYA to 1 MYA	Central Florida (North America)
Stenailurus	1	(?)	(?)
Dinobastis	1	(?)	Asia
Epimachairodus	1	(?)	(?)
Miomachairodus	1	(?)	(?)
Hemimachairodus	1	(?)	(?)
Ischyrosmilus	1	(?)	(?)

Saber-tooth evolutionary tree

File:Fightsabertoothtiger.JPG

A statue of two saber-tooth cats fighting

File:La Brea Saber-tooth Model.JPG

Saber-Tooth model display in the La Brea Tar Pits Museum.

All saber-tooth mammals lived between 33.7 million and 9,000 years ago, but the evolutionary lines that lead 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 ? MYA, in the Cretaceous)
    • Order Sparassodonta (an extinct group of marsupial carnivores)
      • Family Borhyaenidae
      • Family Thylacosmilidae
        • Thylacosmilus
  • Subclass Placentalia
    • Order Creodonta (diverged ? MYA, in the Paleocene)
      • Family Hyaenodontidae
        • Hyaenodon
        • Boualitomus
        • Laekitherium
        • Metapterodon
        • Triacodon
        • Parvagula
    • Order Carnivora
      • Family Nimravidae (diverged from the feliforms 48–55 MYA, 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 ? MYA, in the ?)
            • Tribe Homotheriini
              • Homotherium
              • Machairodus
              • Xenosmilus
            • Tribe Metailurini
              • Dinofelis
              • Metailurus
            • Tribe Smilodontini
              • Megantereon
              • Paramachairodus
              • Smilodon

External links

• Extinct Cats Index
• Illinois State Museum: Saber-toothed Cats
• UC Berkeley Museum of Paleontology: Saber-toothed Cats
• Prehistoric cats and prehistoric cat-like creatures, from the Messybeast Cat Resource Archive.
• Saber-toothed Cats in Cryptozoology