Smilodon

Taxobox
name = "Smilodon"
status = Fossil
fossil_range = Late Pliocene to Late Pleistocene

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image_width = 260px
image_caption = Painting of a "Smilodon" by Charles R. Knight
regnum = Animalia
phylum = Chordata
classis = Mammalia
ordo = Carnivora
familia = Felidae
subfamilia = †Machairodontinae
genus = †"Smilodon"
genus_authority = Lund, 1842
subdivision_ranks = Species
subdivision = †"Smilodon fatalis"
†"Smilodon gracilis"
†"Smilodon populator"

"Smilodon" (PronEng|ˈsmаɪləˌdɒn), sometimes called saber-toothed tiger, is an extinct genus of large machairodontine saber-toothed cats that lived between approximately 2.5 million to 10,000 years ago in North and South America. They are called "saber-toothed" for the extreme length of their maxillary canines. 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. The Natural History Museum of Los Angeles County has many of their complete skeletons.Despite the colloquial name of "saber-toothed tiger", "Smilodon" is not closely related to a tiger, which belongs to another subfamily, the Pantherinae; "Smilodon" is a member of the extinct subfamily Machairodontinae. The name "Smilodon" is a bahuvrihi from Greek: polytonic|σμίλη, "smilē", "chisel" and Greek polytonic|ὀδoύς, ὀδόντος, "odoús", Genitive: "odóntos", "tooth").Among the largest felids, the heaviest specimens of this massively built carnivore may have reached a body mass of up to 400 kg/880 pounds Per Christiansen and John M. Harris: Body Size of Smilodon (Mammalia: Felidae). JOURNAL OF MORPHOLOGY 266:369 –384 (2005) [http://www3.interscience.wiley.com/cgi-bin/abstract/112126332/ABSTRACT?SRETRY=0 online] ] .

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 [A. Turner: "The big cats and their fossil relatives". Columbia University Press, 1997.ISBN 0-231-10229-1] .

* "Smilodon gracilis", 2.5 million-500,000 years ago; the smallest and earliest species with an estimated body mass of only 55-100 kg was probably the successorClarifyme|date=December 2007 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". The estimated body mass for this species ranges from 160 to 220 kg . 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. With an estimated weight of 200 to 300 kg and exceptional large specimens probably up to 400 kg, it was among the heaviest felids to have ever existed .Its upper canines reached 28cm and protruded up to 17 cm out of the upper jaw."

Anatomy

A fully-grown "Smilodon" weighed approximately 55-300 kilograms, depending on species. It had a short tail, powerful legs, muscular neck and long canines. Slightly smaller than a tiger, "Smilodon" was extremely powerful and was quite bear-like in build.

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 in the largest species "Smilodon populator". They were probably built more for stabbing than slashing. Despite being more powerfully built than other large cats "Smilodon" actually had a weaker bite. Modern big cats have more pronounced zygomatic arches, while "Smilodon" had smaller zygomatic arches which restricted the thickness and therefore power of the temporalis muscles, and thus reduced "Smilodon"’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. cite journal | author=Jeff Hecht | title=Sabre-tooth cat had a surprisingly delicate bite | journal=New Scientist | date=1 October 2007 | url=http://www.newscientist.com/article/dn12712-sabretooth-cat-had-a-surprisingly-delicate-bite.html The study used Finite Element Analysis, a computerized technique that is common in engineering.] There seems to a be a general rule that the saber-toothed cats with the largest canines had proportionally weaker bites. However, analyses of canine bending strength (the ability of the canine teeth to resist bending forces without breaking) and bite forces indicate that saber-toothed cats' teeth were stronger "relative to the bite force" than those of modern "big cats". [ cite journal | author=Christiansen, P. | title=Comparative bite forces and canine bending strength in feline and sabretooth felids: implications for predatory ecology | journal=Zoological Journal of the Linnean Society | volume=151 | issue=2 | date=October 2007 | pages=423–437 | doi=10.1111/j.1096-3642.2007.00321.x | url=http://www.ingentaconnect.com/content/bsc/zoj/2007/00000151/00000002/art00007;jsessionid=3fer3dm7dsjm.alexandra ] In addition, "Smilodon" could open its jaws 120 degrees, whereas the lion can only open its jaws to 65 degrees.

Limbs

"Smilodon" had relatively shorter and more massive limbs than other felines. It had well developed flexors and extensorsFact|date=December 2007 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.

Ecology

ocial behavior

The social pattern of this cat is unknown. Some fossils show healed injuries or diseases that would have crippled the animal. Some palaeontologists 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. 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 male-dominated 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.

Diet and hunting

"Smilodon" probably preyed on a wide variety of game including: bison, elk, deer, American camels, horses, ground sloths and the (Jeffersonian mammoth, imperial mammoth, Columbian mammoth, Woolly mammoth), and mastodons.

Modern big cats kill mainly by strangling their victims, which may take a few minutes. "Smilodon"’s jaw muscles were probably too weak for this and its long canines would have been vulnerable to snapping in a prolonged struggle. Research in 2007 concluded that "Smilodon" more probably used its great upper-body strength to wrestle prey to the ground, where its long canines could deliver a deep stabbing bite to the throat which would generally cut through the jugular vein and / or the trachea and thus kill the prey very quickly. cite journal | author=McHenry, C.R., Wroe S., Clausen, P.D., Moreno, K. and Cunningham, E. | title=Supermodeled sabercat, predatory behavior in "Smilodon fatalis" revealed by high-resolution 3D computer simulation | journal=PNAS | date=October 2007 | doi=10.1073/pnas.0706086104 | url=http://www.pnas.org/cgi/content/abstract/0706086104v1 | volume=104 | pages=16010 | pmid=17911253] The leaders of this study also commented to scientific journalists that this technique may have made "Smilodon" a more efficient killer of large prey than modern lions or tigers, but also made it more dependent on the supply of large animals. This highly-specialized hunting style may have contributed to its extinction, as "Smilodon"’s cumbersome build and over-sized canines would have made it less efficient at killing smaller, faster prey if the ecosystem changed for any reason.

Extinction

"Smilodon" became extinct around 10,000 BC, which saw the extinction of many other large herbivorous and carnivorous mammals.

Often prehistoric humans, which reached North America at the end of the Ice age, are supposed to be responsible for this extinction wave. Others 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 grasslandssic. 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 hypothesis does not explain how "Smilodon" and its ancestors successfully survived many previous interglacials.

Popular culture

"Smilodon" appears in various kinds in popular culture. Several Smilodon appear in the animated film "Ice Age", most notably Diego (Denis Leary), one of the main characters, who also appears in the sequel, "". In the 1977 movie "Sinbad and the Eye of the Tiger", the climax takes place in the citadel of a giant "Smilodon". The creature is brought to life by Ray Harryhausen's stop motion effects. The movie "Sabretooth" featured a "Smilodon" that was brought back to life from fossilized DNA.

"Smilodon" has appeared also as one of the main creatures of Impossible Pictures films "Walking With Beasts" and "Prehistoric Park" (fourth episode). Strangely, the former depicts "Smilodon" as living and hunting in groups like lions, but the latter depicts them hunting "Toxodon" alone.

"Smilodon" was also featured in the hit ITVseries "Primeval", seen in episode 9. A woman named Valerie finds a young smilodon cub in her garage after it stumbled into an anomaly (portal in time) she raised it from a young age, keeping it hidden from the outside world in her house in the forest. However, once the creature grew to a significant size, it escaped and attacked visitors at a nearby amusement park. Although Valerie treated it like her own special companion, after she ordered it to attack Nick Cutter, it turned on her and mauled her to death.

The sabertoothed cat that appears in the 2008 movie "10,000 BC" has been incorrectly said to be a Smilodon. In fact, it is a fictional cat designed specially for the movie, larger and more tiger-like than Smilodon.

Grune The Destroyer, the ghost warrior, from the highly popular classic animated series "Thundercats" is an anthropomorphic Saber-toothed tiger, villain and former Thundercat who once fought the Thundercats after escaping his tomb inside a giant tree on Third Earth. Once battled Jaga the previous Lord Of The Thundercats in a titanic battle lasting for days. wields a 'spiked' battle club/mace as his choice of weapon.

A new monster named "Smilodon" was added in the MMORPG "Final Fantasy XI" expansion Wings of the Goddess. It is a member of the Tiger family, all of which more closely resemble saber-toothed cats than modern-day tigers. [ [http://wiki.ffxiclopedia.org/wiki/Smilodon FFXIclopedia - Smilodon] ]

Jeff Rovin's novel "Fatalis" is based around a family of sabre-toothed cats coming into a conflict with humans in modern-day Southern California.

External links

* [http://w210.ub.uni-tuebingen.de/dbt/volltexte/2003/828/pdf/Diplomarbeit.pdf Schneider, Jens, "Killing behavior in "Smilodon fatalis" (Mammalia, Carnivora, Felidae) based on functional anatomy and body proportions of the front- and hind limbs" Diploma thesis in german language]
* [http://studentwebs.coloradocollege.edu/~a_neuman/ Sabre-toothed cats]
* [http://www.bluelion.org/smilodon.htm "Smildon" article at bluelion.org]
* [http://www.westerncentermuseum.org/exhibit.html Western Center for Archaeology and Paleontology] Hemet, CA