Anachlysictis
| Anachlysictis | |
|---|---|
| |
| The holotype lower jaw | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | †Sparassodonta |
| Family: | †Thylacosmilidae |
| Genus: | †Anachlysictis Goin, 1997 |
| Species: | †A. gracilis
|
| Binomial name | |
| †Anachlysictis gracilis Goin, 1997
| |
Anachlysictis gracilis is an
metatherians (a group including marsupials and their close relatives) that inhabited South America during the Cenozoic. Anachlysictis is the first record of such borhyaenoids in northern South America, and also the most primitive known member of the family Thylacosmilidae, a group of predators equipped with "saber teeth". It was also the only confirmed record of a thylacosmilid that did not belong to the genus Thylacosmilus until the official publication of Patagosmilus in 2010.[1]
This species was found in the
Villavieja Formation in the area of La Venta in Colombia, a famous fossil deposit in the Middle Miocene (Laventan; 13.8–11.8 million years ago),[2] based on fragments that include a front portion of the lower jaw, with an incipient molar tooth and a piece of carnassial from the front of the maxilla.[3]
Description
Anachlysictis, was smaller than its better-known relative masseter muscle (involved in the movements of the jaw) was reduced.[5] This is because, as in other predatory saber-toothed species, this muscle is reduced, leaving more space for the jaw joint to increase its opening angle and letting the well-developed neck muscles bring down the skull and allow the fangs to bite into the flesh of their prey.[citation needed]
Taxonomy
Until the discovery of Anachlysictis, it was supposed that Thylacosmilus was a close relative of the family
Borhyaenoidea, whose monophyly needs review. The pattern of the molars of Anachlysictis is very similar to that of the little-known methatherian Hondadelphys, also from the Honda Group at the Konzentrat-Lagerstätte La Venta. This was originally considered to be a species of opossum, but is now considered a primitive sparassodont, so Hondadelphys could well represent the sister clade of Thylacosmilidae.[5]
References
- ^ Forasiepi A. & Carlini A. A new thylacosmilid (Mammalia, Metatheria, Sparassodonta) from the Miocene of Patagonia, Argentina. Zootaxa 2552: 55–68 (2010)
- ^ Anachlysictis gracilis at Fossilworks.org
- ^ Goin, F. J. (1997). New clues for understanding Neogene marsupial radiations. In: Vertebrate Paleontology in the Neotropics. The Miocene Fauna of La Venta, Colombia, R. F. Kay, R. Cifelli, R. H. Madden, and J. Flynn, eds., pp. 185-204, Smithsonian Institution Press, Washington, DC.
- ^ Wroe, S., Argot, C., & Dickman, C. (2004). On the rarity of big fierce carnivores and primacy of isolation and area: tracking large mammalian carnivore diversity on two isolated continents. Proceedings of the Royal Society B Biological Sciences, 271(1544), 1203-1211.
- ^ a b Goin, F.J. 2003. Early marsupial radiations in South America. En: M. Jones, C. Dickman y M. Archer (eds.), Predators with Pouches, The Biology of Carnivorous Marsupials, CSIRO Publishing, Australia, pp. 30–42.
External links
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