Thylacosmilus Fossil range: Miocene–Early Pleistocene PreЄ Є O S D C P T J K Pg N
Thylacosmilus atrox and Mesotherium
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Infraclass:	Metatheria
Order:	Sparassodonta
Family:	Thylacosmilidae
Genus:	Thylacosmilus Riggs, 1933
Species
T. atrox T. lentis

Thylacosmilus atrox skull, American Museum of Natural History.

Thylacosmilus.

Thylacosmilus ("pouch sabre") was a genus of sabre-toothed metatherian predators that first appeared during the Miocene. Remains of the animal have been found in parts of South America, primarily Argentina. It was not a relative of the true saber-tooth cat, which it resembles only because of convergent evolution.

[edit] Description

Thylacosmilus had long, sabre-like upper canines and short, blunt, peg-like lower canines. The incisors were missing altogether and the other teeth were severely reduced, but, as distinct from machairods, their number was complete.^[1]

Thylacosmilus' sabre-teeth kept growing throughout its life, unlike the sabres of true saber-tooths. It also had a pair of elongated, scabbard-like flanges growing from the lower jaw, which protected the sabre-teeth when it closed its mouth. The cervical vertebrae were very strong and to some extent resembled the vertebrae of machairods. ^[1]

It became extinct during the early Pleistocene as a result of the Great American Interchange, being outcompeted by true sabre-tooth cats such as Smilodon.^{[citation needed]}

[edit] References

• Evolution of the Earth by Donald R. Prothero, Jr., Robert H. Dott, Donald Prothero, and Jr., Robert Dott
• The Earth Through Time by Harold L. Levin
• Bringing Fossils To Life: An Introduction To Paleobiology by Donald R. Prothero

[edit] External links

• Thylacosmilus (marsupial sabre-tooth)
• Art by Maximo Salas
• Skull of Thylacosmilus
• Comparison of Thylacosmilus (upper) and Smilodon (below)

Wikispecies has information related to: Thylacosmilus

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