Smilodon

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Smilodon Fossil range: Late Pliocene to Late Pleistocene
Painting of a Smilodon.
Conservation status
Fossil
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Carnivora Family: Felidae Subfamily: †Machairodontinae Genus: †Smilodon Lund, 1842
Species
†Smilodon fatalis †Smilodon gracilis †Smilodon populator

Smilodon (pronounced /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, but is a member of the extinct subfamily Machairodontinae. The name Smilodon is a bahuvrihi from Greek: σμίλη, smilē, "chisel" and Greek ὀδoύς, ὀδόντος, odoús, Genitive: odóntos, "tooth"). It was among the largest felids, the heaviest specimens of this massively built carnivore may have reached a body mass of up to 400 kg ^[1].

Contents 1 Classification and species 2 Anatomy 2.1 Teeth and jaws 2.2 Limbs 3 Ecology 3.1 Social behaviour 3.2 Diet and hunting 4 Extinction 5 Popular Culture 6 References 7 External links

[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^[2].

• Smilodon gracilis, 2.5 million-500,000 years ago; the smallest and earliest species with an estimated body mass of only 55-100 kg ^[1] 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. The estimated body mass for this species ranges from 160 to 220 kg ^[1]. 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 ^[1].Its upper canines reached 28cm and protruded up to 17 cm out of the upper jaw.

[edit] 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.

[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 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.^[3] 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".^[4] In addition, Smilodon could open its jaws 120 degrees, whereas the lion can only open its jaws to 65 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] Social behaviour

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.

[edit] Diet and hunting

Smilodon probably preyed on a wide variety of game including: bison, elk, deer, American camels, horses, ground sloths and the young of mammoths (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 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.^[5] 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.^[3]

[edit] Extinction

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

Others^[who?] 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

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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, Ice Age 2: The Meltdown. 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 a anthropomorphic Sabre-toothed tiger, villain and former Thundercat who once fought the Thundercats after escaping his tomb inside a giant tree on 3rd 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.^[6]

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.

[edit] References

[edit] External links

• 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
• Sabre-toothed cats
• Smildon article at bluelion.org
• Western Center for Archaeology and Paleontology Hemet, CA