Thylacosmilus
Thylacosmilus is a extinct genus of carnivorous sparassodont.[1] found as fossils in deposits dated from about 10 million to 3 million years ago (late Miocene to late Pliocene epoch) in Argentina, South America.
| Thylacosmilus | |
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| Thylacosmilus atrox Field Museum of Natural History | |
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| Family: | Thylacosmilidae
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| Genus: | Thylacosmilus Riggs, 1933
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Thylacosmilus was sabre-toothed and was about as large as a modern jaguar. To a remarkable degree, Thylacosmilus paralleled the evolution of felid sabre-toothed cats like Smilodon. Its canine teeth were long and powerfully developed; they were used for stabbing prey. Its killing method was to hold its prey, and make deep bites into the soft tissue driven by powerful neck muscles.[2][3] The canine teeth were protected by a well-developed flange, or projecting edge, in the chin region of the lower jaw. The canines continued to grow during adult life, which they do not in marsupials or placental mammals.[4]
Thylacosmilus died out during the late Pliocene, whereas saber-toothed cats did not get to South America until the middle Pleistocene epoch.[5][6] As a result, the last appearance of Thylacosmilus is separated from the first appearance of Smilodon by over one and a half million years.
Thylacosmilus Media
Partially reconstructed holotype skull, Field Museum of Natural History
Holotype skull in multiple views
Comparison of the skulls of the two saber toothed mammals Megantereon and Thylacosmilus
Atlas, axis, and limb bones; the outlines of the missing foot bones are restored after the thylacine
Cladosictis (white background)
Life reconstruction of Thylacosmilus atrox
Skeletal reconstruction of Thylacosmilus atrox. Missing parts based on other members of Sparassodonta.
Size of Thylacosmilus compared to a human
Details in the skull and teeth, compared with Megantereon
Skull cast mounted with open jaws, North American Museum of Ancient Life
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References
- ↑ The Sparassodonta were actually not marsupials, but a sister group which used to be described as marsupials.
- ↑ Hogenboom, M. (2013). "Sabretooth killing power depended on thick neck". BBC. Retrieved 2013-08-03.
- ↑ Wroe, S.; et al. (2013). "Comparative biomechanical modeling of metatherian and placental saber-tooths: a different kind of bite for an extreme pouched predator". PLOS ONE. 8 (6): e66888. doi:10.1371/journal.pone.0066888. PMC 3694156. PMID 23840547.
- ↑ Sparassodonts did not have the regular two-stage growth pattern of modern mammals.
- ↑ see Great American Interchange.
- ↑ Prevosti, Francisco J; Forasiepi, Analia & Zimicz, Natalia 2013. The evolution of the Cenozoic terrestrial mammalian predator guild in South America: competition or replacement?. Journal of Mammalian Evolution 20: 3–21. [1]