Smilodon

From Wikipedia, the free encyclopedia

Image:Broom icon.svg

This article may require cleanup to meet Wikipedia's quality standards. Please improve this article if you can. (December 2007)

Image:Wiki letter w.svg

Please help improve this article or section by expanding it. Further information might be found on the talk page or at requests for expansion. (December 2007)

Smilodon
Image:Smilodon californicus.jpg Smilodon californicus fossil at the National Museum of Natural History, Washington, DC
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Carnivora Family: Felidae Subfamily: Machairodontinae Genus: Smilodon Lund, 1842
Species
Smilodon californicus Smilodon fatalis Smilodon gracilis Smilodon populator Smilodon floridus

For the record label, see Smilodon Records

Smilodon (pronounced /ˈsmаɪləˌdɒn/), saber-toothed cat or saber-toothed tiger is an extinct genus of large machairodontine saber-toothed cats that are understood to have lived between approximately 3 million to 10,000 years ago in North and South America. They are called "saber-toothed" for the extreme length of their maxillary canines. Because of the large number of fossils found, Smilodon is well-known to researchers.^[1] Despite the colloquial name of "saber-toothed tiger", it is actually not closely related to the modern tiger, nor to other modern cats.^[2]. The name Smilodon is a bahuvrihi from Ancient Greek: σμίλη, smilē, "knife" and (Ionic Greek) ὀδών, odon, "tooth") .

Contents 1 Classification and species 2 Anatomy 2.1 Teeth and jaws 2.2 Limbs 3 Ecology 3.1 Habitat 3.2 Social behavior 3.3 Diet and hunting 4 La Brea tar pits 5 Extinction 6 Popular Culture 7 References 8 Notes

[edit] Classification and species

The genus Smilodon was described by the Danish naturalist and palaeontologist Peter Wilhelm Lund in 1841. He found the fossils of Smilodon populator in caves near the small town of Lagoa Santa, in the state of Minas Gerais, Brazil.

Several Smilodon species have been described, but today usually only three species are distinguished^[3].

• Smilodon gracilis, 2.5 million-500,000 years ago; the smallest and earliest species was probably the successor^[clarify] of Megantereon. The other Smilodon species probably derived from this species.
• Smilodon fatalis, 1.6 million-10,000 years ago, replaced Smilodon gracilis in North America and Western South America. In size it was between Smilodon gracilis and Smilodon populator. Sometimes two additional species are recognized, Smilodon californicus and Smilodon floridus, but usually they are considered to be subspecies of Smilodon fatalis.
• Smilodon populator, 1 million-10,000 years ago; occurred in the eastern parts of South America and was the largest species of all Machairodonts. Its upper canines reached 28cm and protruded up to 17 cm out of the upper jaw.

[edit] Anatomy

A fully-grown Smilodon weighed approximately 200 kilograms (450 pounds) and had a short tail, powerful legs, muscular neck and long canines. Slightly smaller than a lion, Smilodon was extremely powerful and was quite bear-like in build.

[edit] Teeth and jaws

Smilodon is most famous for its relatively long canines. They are the longest canines of the saber-toothed cats at about 17 cm (7 inches) long. They were built more for stabbing than slashing. A smilodon could not bite into prey and rip and shred like most big cats today. If a smilodon did indeed slash around, its huge canines would break in half. When killing, the neck muscles were used more than the jaw muscles, giving smilodon the ability to bite and bring its neck down, thus delivering a more powerful attack. Despite being more powerfully built than other large cats Smilodon actually had a weaker bite. Modern big cats have more pronounced zygomatic arches. By comparison; Smilodon had smaller zygomatic arches which reduces the temporalis muscle's available space and thus reduces the cat's bite force. Analysis of its narrow jaws indicates that it could produce a bite only a third as strong of that of a lion.^[4] This could explain why the feline evolved such long teeth. In addition, Smilodon could open its jaws 120 degrees.

[edit] Limbs

Smilodon had relatively shorter and more massive limbs than other felines. It had well developed flexors and extensors^{[citation needed]} in its forepaws, which enabled it to pull down large prey. The back limbs had powerfully built adductor muscles which might have helped the cat's stability when wrestling with prey. Like most cats, its claws were retractable.

[edit] Ecology

[edit] Habitat

Smilodon or saber-toothed tiger most likely lived in grasslands, or pine forests with rocky soil. A majority of fossils have been discovered in areas such as these.^{[citation needed]}

[edit] Social behavior

The social pattern of this cat is unknown. Some fossils show healed injuries or diseases that would have crippled the animal. Some paleontologists see this as evidence that saber-toothed cats were social animals, living and hunting in packs that provided food for old and sick members. Living in groups would also help with having to compete with lions and wolves.^[5]

The canine teeth and body size of Smilodon were about the same in both male and female cats. This indicates that Smilodon may not have lived in groups (and that the teeth may not have been used for attracting mates as it has been suggested). However, it still could have hunted cooperatively.

[edit] Diet and hunting

Smilodon probably preyed on a wide variety of game including: bison, elk, deer, American camels, horses, ground sloth and the young of elephants (including the imperial mammoth, Jeffersonian mammoth, Columbian mammoth, woolly mammoth, and the mastodon).

Recent investigations suggest that this saber-toothed cat probably used its long canines to slash through the throat, severing the trachea and cutting the jugular.^{[citation needed]} Its teeth were surprisingly delicate and could easily snap off if a prey animal struggled. As noted above, its mouth could open up to 120 degrees, whereas the lion can only open its jaws to 65 degrees.

Stress patterns on Smilodon bones indicate that it used its powerfully built forelegs to subdue its prey, making it easier to use its teeth.^[6] Its short tail indicates that it was an ambush hunter rather than a runner.

[edit] La Brea tar pits

The La Brea tar pits in Los Angeles trapped hundreds of Smilodon in the tar, possibly as they tried to feed on mammoths already trapped. There is a museum there today which has many of their complete skeletons.

[edit] Extinction

Smilodon became extinct around 10,000 years ago. Some^{[attribution needed]} have suggested that humans could have indirectly contributed to its extinction, either by hunting the cat's main prey or by infecting the population with a virus.^{[citation needed]}

Others^{[attribution needed]} have suggested that the end of the ice age caused the extinction. As the ice age ended there would have been shrinking environments and changing vegetation patterns. Extensive grasslands, with different types of grasses, and isolated forests replaced healthy mixes of forests and grasslands^[sic]. The summer and winter both became more extreme and North America began to dry out or begin to be covered in snow, thus denying food sources for mammoths and in turn Smilodon. However, this theory does not explain how Smilodon and its ancestors successfully survived many previous interglacials.

[edit] Popular Culture

• Mighty Morphin Power Rangers (Saber-Toothed Tiger Dinozord)/Kyōryū Sentai Zyuranger (Guardian Beast SaberTiger)
• Dinozaurs (Dino Saber and Drago Tigra)
• Dino-Riders
• Prehistoric Park
• Zoo Tycoon 2: Extinct Animals

[edit] References

[edit] Notes

br:Tigr dent sabrenn

ca:Smilodon cs:Šavlozubý tygr da:Smilodon de:Smilodon es:Smilodon eo:Smilodonto fr:Tigre à dents de sabre it:Smilodon nl:Sabeltandtijger ja:スミロドン no:Smilodon pl:Smilodon pt:Smilodon ru:Смилодон sh:Smilodon fi:Smilodon sv:Smilodon vi:Smilodon zh:劍齒虎