Instruct: Given a question, retrieve passages that answer the question.
Query: How large was the Smilodon?
Overall, Smilodon was more robustly built than any extant cat, with particularly well-developed forelimbs and exceptionally long upper canine teeth. Its jaw had a bigger gape than that of modern cats, and its upper canines were slender and fragile, being adapted for precision killing. S.gracilis was the smallest species at 55 to 100kg (120 to 220lb) in weight. S.fatalis had a weight of 160 to 280kg (350 to 620lb) and height of 100cm (39in). Both of these species are mainly known from North America, but remains from South America have also been attributed to them. S.populator from South America was the largest species, at 220 to 400kg (490 to 880lb) in weight and 120cm (47in) in height, and was among the largest known felids. The coat pattern of Smilodon is unknown, but it has been artistically restored with plain or spotted patterns.
In North America, Smilodon hunted large herbivores such as bison and camels, and it remained successful even when encountering new prey species in South America. Smilodon is thought to have killed its prey by holding it still with its forelimbs and biting it, but it is unclear in what manner the bite itself was delivered. Scientists debate whether Smilodon had a social or a solitary lifestyle; analysis of modern predator behavior as well as of Smilodon's fossil remains could be construed to lend support to either view. Smilodon probably lived in closed habitats such as forests and bush, which would have provided cover for ambushing prey. Smilodon died out at the same time that most North and South American megafauna disappeared, about 10,000 years ago. Its reliance on large animals has been proposed as the cause of its extinction, along with climate change and competition with other species, but the exact cause is unknown.
Smilodon is a genus of the extinct machairodont subfamily of the felids. It is one of the most famous prehistoric mammals, and the best known saber-toothed cat. Although commonly known as the saber-toothed tiger, it was not closely related to the tiger or other modern cats. Smilodon lived in the Americas during the Pleistocene epoch (2.5 mya–10,000 years ago). The genus was named in 1842, based on fossils from Brazil. Three species are recognized today: S.gracilis, S.fatalis, and S.populator. The two latter species were probably descended from S.gracilis, which itself probably evolved from Megantereon. The hundreds of individuals obtained from the La Brea Tar Pits in Los Angeles constitute the largest collection of Smilodon fossils.
Sinbad and his friends arrive minutes later, and realize Zenobia has entered the pyramid. They enter the shrine's main chamber, the interior of which is covered in ice and is guarded by a "Smilodon" frozen in a block of ice. Zenobia orders Rafi to attack Melanthius and is about to hurt Dione with a knife, but he is attacked by Kassim and is killed falling down the temple stairs. Momentarily overcome with grief, Zenobia cradles her son while Sinbad and Melanthius investigate how to get Kassim into the column of light at the top of the shrine which will break the spell. Having come to her senses again and seeing Kassim restored to human form, Zenobia transfers her spirit into the "Smilodon". Breaking free of its icy prison, the giant cat attacks the group but the troglodyte then enters the scene and engages the "Smilodon" in combat. Initially gaining the upper hand and even slamming the creature to the ground, the "Smilodon" disarms the troglodyte of its spear and pins it to the wall, inflicting more damage before killing it via biting the neck. Sinbad and his men fight against the "Smilodon" but are overpowered by its speed and Maroof is killed. The "Smilodon" then attacks Sinbad who uses the troglodyte's spear to jab it in the chest, killing both the "Smilodon" and Zenobia. With the spell on Kassim broken and Zenobia dead, the adventurers flee the temple as it collapses and is buried in snow and ice.
In his 1880 article about extinct cats, Cope also named a third species of Smilodon, S.gracilis. The species was based on a partial canine, which had been obtained in a cave near the Schuylkill River in Pennsylvania. Cope found the canine to be distinct from that of the other Smilodon species due to its smaller size and more compressed base.[7] Its specific name refers to the species' lighter build.[9] This species is known from fewer and less complete remains than the other members of the genus.[10] S.gracilis has at times been considered part of genera such as Megantereon and Ischyrosmilus.[11] S.populator, S.fatalis and S.gracilis are currently considered the only valid species of Smilodon, and features used to define most of their junior synonyms have been dismissed as variation between individuals of the same species (intraspecific variation).[4][3] One of the most famous of prehistoric mammals, Smilodon has often been featured in popular media and is the state fossil of California.[1]
Whether Smilodon was sexually dimorphic has implications for its reproductive behavior. Based on their conclusions that Smilodon fatalis had no sexual dimorphism, Van Valkenburgh and Sacco suggested in 2002 that, if the cats were social, they would likely have lived in monogamous pairs (along with offspring) with no intense competition among males for females.[26] Likewise, Meachen-Samuels and Binder (2010) concluded that aggression between males was less pronounced in S.fatalis than in the American lion.[27] Christiansen and Harris (2012) found that, as S.fatalis did exhibit some sexual dimorphism, there would have been evolutionary selection for competition between males.[28] The structure of the hyoid bones suggest that Smilodon communicated by roaring, like modern big cats.[68] The ability to roar may have implications for the social life of Smilodon.[69]
The dirk-toothed machairodonts, including Smilodon, Megantereon, and Paramachairodus, are defined by sturdiness and strength with the most primitive (Paramachairodus) being smaller and more lithe than the more advanced Smilodon; the intermediate Megantereon falls in between. They were not stamina runners with short tarsi and metatarsi and heavy bodies. When compared with the modern lion, their ribcages were barrel-like with narrow anterior ends and expanded posterior ends. Their scapulae were very well developed, especially in Smilodon, to allow for a larger surface area of attachment for massive shoulder and triceps muscles. The cervical vertebrae are very sturdy, and the attachments for muscles were powerful and strong. The lumbar section of the vertebral column was shortened. The tails were, from most primitive to most advanced, growing shorter and shorter, resulting in the bobcat-like tail of Smilodon. When viewing only postcranial remains, they are more similar in structure to modern bears than to modern cats.[26]
The earliest felids are known from the Oligocene of Europe, such as Proailurus, and the earliest one with saber-tooth features is the Miocene genus Pseudaelurus.[4] The skull and mandible morphology of the earliest saber-toothed cats was similar to that of the modern clouded leopards (Neofelis). The lineage further adapted to the precision killing of large animals by developing elongated canine teeth and wider gapes, in the process sacrificing high bite force.[14] As their canines became longer, the bodies of the cats became more robust for immobilizing prey.[13] In derived smilodontins and homotherins, the lumbar region of the spine and the tail became shortened, as did the hind limbs.[4] Based on mitochondrial DNA sequences extracted from fossils, the lineages of Homotherium and Smilodon are estimated to have diverged about 18 Ma ago.[15] The earliest species of Smilodon is S.gracilis, which existed from 2.5 million to 500,000 years ago (early Blancan to Irvingtonian ages) and was the successor in North America of Megantereon, from which it probably evolved. Megantereon itself had entered North America from Eurasia during the Pliocene, along with Homotherium. S.gracilis reached the northern regions of South America in the Early Pleistocene as part of the Great American Interchange.[16][13] The younger Smilodon species are probably derived from S.gracilis.[17] S.fatalis existed 1.6 million–10,000 years ago (late Irvingtonian to Rancholabrean ages), and replaced S.gracilis in North America.[8] S.populator existed 1 million–10,000 years ago (Ensenadan to Lujanian ages); it occurred in the eastern parts of South America.[18]
Several Smilodon fossils show signs of ankylosing spondylitis, hyperostosis and trauma;[74] some also had arthritis, which gave them fused vertebrae. One study of 1,000 Smilodon skulls found that 30% of them had eroded parietal bones, which is where the largest jaw muscles attach. They also showed signs of microfractures, and the weakening and thinning of bones possibly caused by mechanical stress from the constant need to make stabbing motions with the canines.[75] Bony growths where the deltoid muscle inserted in the humerus is a common pathology for a La Brea specimen, which was probably due to repeated strain when Smilodon attempted to pull down prey with its forelimbs. Sternum injuries are also common, probably due to collision with prey. Some bones also show evidence of having been bitten by other Smilodon, with one skull showing an unhealed wound from a canine, seemingly fatal, and a scapula from the same site that had been pierced by a canine.[45] The frequency of trauma in S. fatalis specimens was 4.3%, compared to 2.8% in the dire wolf, which implies the ambush predatory behavior of the former led to greater risk of injury than the pursuit predatory behavior of the latter. Smilodon remains exhibit relatively more shoulder and lumbar vertebrae injuries.[76]
S.populator was very successful, while Homotherium never became widespread in South America. The extinction of the thylacosmilids has been attributed to competition with Smilodon, but this is probably incorrect, as they seem to have disappeared before the arrival of the large cats. The phorusrhacid "terror birds" may have dominated the large predator niche in South America until Smilodon arrived.[13] S. populator may have been able to reach larger size than S. fatalis due to a lack of competition in Pleistocene South America; S. populator arrived after the extinction of Arctotherium angustidens, one of the largest carnivores ever, and could therefore assume the niche of mega-carnivore.[79] S. populator preferred large prey from open habitats such as grassland and plains, based on evidence gathered from isotope ratios that determined the animal's diet. In this way, the South American Smilodon species was probably similar to the modern lion. S. populator probably competed with the canid Protocyon there, but not with the jaguar, which fed primarily on smaller prey.[81][82]
Felidae Proailurus Pseudaelurus Panthera (tigers, lions, jaguars, and leopards) Caracal Leopardus (ocelot and relatives) Felis (domestic cats and relatives) Herpailurus (jaguarundi) Miracinonyx (American cheetah) Puma (cougar) Dinofelis Nimravides Machairodus Homotherium Xenosmilus Paramachairodus Megantereon Smilodon gracilis Smilodon populator Smilodon fatalis
Debate continues as to how Smilodon killed its prey. Traditionally, the most popular theory is that the cat delivered a deep stabbing bite or open-jawed stabbing thrust to the throat, generally cutting through the jugular vein and/or the trachea and thus killing the prey very quickly.[49][50] Another hypothesis suggests that Smilodon targeted the belly of its prey. This is disputed, as the curvature of their prey's belly would likely have prevented the cat from getting a good bite or stab.[51] In regard to how Smilodon delivered its bite, the "canine shear-bite" hypothesis has been favored, where flexion of the neck and rotation of the skull assisted in biting the prey, but this may be mechanically impossible. The mandibular flanges may have helped resist bending forces when the mandible was pulled against the hide of a prey.[52] The protruding incisors were arranged in an arch, and were used to hold the prey still and stabilize it while the canine bite was delivered. The contact surface between the canine crown and the gum was enlarged, which helped stabilize the tooth and helped the cat sense when the tooth had penetrated to its maximum extent. Since saber-toothed cats generally had a relatively large infraorbital foramen (opening) in the skull, which housed nerves associated with the whiskers, it has been suggested the improved senses would have helped the cats' precision when biting outside their field of vision, and thereby prevent breakage of the canines. The blade-like carnassial teeth were used to cut skin to access the meat, and the reduced molars suggest that they were less adapted for crushing bones than modern cats.[45] As the food of modern cats enters the mouth through the side while cutting with the carnassials, not the front incisors between the canines, the animals do not need to gape widely, so the canines of Smilodon would likewise not have been a hindrance when feeding.[36]
The latest Smilodon fatalis specimen recovered from the Rancho La Brea tar pits has been dated to 13,025 years ago.[85] The latest Smilodon populator remains found in the cave of Cueva del Medio, near the town of Soria, northeast Última Esperanza Province, Magallanes Region in southern-most Chile, and have been dated 10,935–11,209 years ago.[86]
Traditionally, saber-toothed cats have been artistically restored with external features similar to those of extant felids, by artists such as Charles R. Knight in collaboration with various paleontologists in the early 20th century.[34] In 1969, paleontologist G.J. Miller instead proposed that Smilodon would have looked very different from a typical cat and similar to a bulldog, with a lower lip line (to allow its mouth to open wide without tearing the facial tissues), a more retracted nose and lower-placed ears.[35] Paleoartist Mauricio Antón and coauthors disputed this in 1998 and maintained that the facial features of Smilodon were overall not very different from those of other cats. Antón noted that modern animals like the hippopotamus are able to achieve a wide gap without tearing tissue by the moderate folding of the orbicularis oris muscle, and such a muscle configuration exists in modern large felids.[36] Antón stated that extant phylogenetic bracketing (where the features of the closest extant relatives of a fossil taxon are used as reference) is the most reliable way of restoring the life-appearance of prehistoric animals, and the cat-like Smilodon restorations by Knight are therefore still accurate.[34]
The brain of Smilodon had sulcal patterns similar to modern cats, which suggests an increased complexity of the regions that control the sense of hearing, sight, and coordination of the limbs. Felid saber-tooths in general had relatively small eyes that were not as forward-facing as those of modern cats, which have good binocular vision to help them move in trees.[45] Smilodon was likely an ambush predator that concealed itself in dense vegetation, as its limb proportions were similar to modern forest dwelling cats,[46] and its short tail would not have helped it balance while running.[47] Unlike its ancestor Megantereon, which was at least partially scansorial and therefore able to climb trees, Smilodon was probably completely terrestrial due to its greater weight and lack of climbing adaptations.[48] The heel bone of Smilodon was fairly long, which suggests it was a good jumper.[23] Its well-developed flexor and extensor muscles in its forearms probably enabled it to pull down, and securely hold down, large prey. Analysis of the cross-sections of S.fatalis humeri indicated that they were strengthened by cortical thickening to such an extent that they would have been able to sustain greater loading than those of extant big cats, or of the extinct American lion. The thickening of S.fatalis femurs was within the range of extant felids.[49] Its canines were fragile and could not have bitten into bone; due to the risk of breaking, these cats had to subdue and restrain their prey with their powerful forelimbs before they could use their canine teeth, and likely used quick slashing or stabbing bites rather than the slow, suffocating bites typically used by modern cats.[49] On rare occasions, as evidenced by fossils, Smilodon was willing to risk biting into bone with its canines. This may have been focused more towards competition such as other Smilodon or potential threats such as other carnivores than on prey.[48]
An apex predator, Smilodon primarily hunted large mammals. Isotopes preserved in the bones of S.fatalis in the La Brea Tar Pits reveal that ruminants like bison (Bison antiquus, which was much larger than the modern American bison) and camels (Camelops) were most commonly taken by the cats there.[38] In addition, isotopes preserved in the tooth enamel of S.gracilis specimens from Florida show that this species fed on the peccary Platygonus and the llama-like Hemiauchenia.[39] In rare cases, Smilodon may have also targeted glyptodonts, based on a Glyptotherium skull that bears elliptical puncture marks[40] consistent with the size and diameter of its canine teeth.[41] This was a juvenile glyptodont with an incompletely developed cephalic shield (head armor).[40] Isotopic studies of dire wolf (Canis dirus) and American lion (Panthera leo atrox) bones show an overlap with S.fatalis in prey, which suggests that they were competitors.[38] The availability of prey in the Rancho La Brea area was likely comparable to modern East Africa.[42] As Smilodon migrated to South America, its diet changed; bison were absent, the horses and proboscideans were different, and native ungulates such as toxodonts and litopterns were completely unfamiliar, yet S.populator thrived as well there as its relatives in North America.[13] The differences between the North and South American species may be due to the difference in prey between the two continents.[8] Smilodon probably avoided eating bone and would have left enough food for scavengers.[43] Smilodon itself may have scavenged dire wolf kills.[44] It has been suggested that Smilodon was a pure scavenger that used its canines for display to assert dominance over carcasses, but this theory is not supported today as no modern terrestrial mammals are pure scavengers.[45]
Regions Bank and UBS maintained a display in their first floor lobby that included bones from the "Smilodon" and other faunal material from the site. In 2016, the display was moved to Bridgestone Arena. "Smilodon" remains on display include portions of the lower jaw and molars, vertebral column, ribs, humerus, metacarpals, and metatarsals. A replica of a "Smilodon" skull from the La Brea Tar Pits serves as the centerpiece of the display. The Smilodon upper canine that led to the site discovery in 1971 is not on display, and is apparently no longer in the collection. Conventional wisdom among bank and facility management personnel is that the canine is now in the collection of the Smithsonian; however, that institution holds no record of the artifact.
Despite being more powerfully built than other large cats, Smilodon had a weaker bite. Modern big cats have more pronounced zygomatic arches, while these were smaller in Smilodon, 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 as that of a lion (the bite force quotient measured for the lion is 112).[53][54] There seems to be a general rule that the saber-toothed cats with the largest canines had proportionally weaker bites. Analyses of canine bending strength (the ability of the canine teeth to resist bending forces without breaking) and bite forces indicate that the saber-toothed cats' teeth were stronger relative to the bite force than those of modern big cats.[55] In addition, Smilodon's gape could have reached almost 120 degrees,[56] while that of the modern lion reaches 65 degrees.[57] This made the gape wide enough to allow Smilodon to grasp large prey despite the long canines.[36] A 2018 study compared the killing behaviour of Smilodon fatalis and Homotherium serum, and found that the former had a strong skull with little trabecular bone for a stabbing canine-shear bite, whereas the latter had more trabecular bone and used a clamp and hold style more similar to lions. The two would therefore have held distinct ecological niches.[58]
Along with most of the Pleistocene megafauna, Smilodon became extinct 10,000 years ago in the Quaternary extinction event. Its extinction has been linked to the decline and extinction of large herbivores, which were replaced by smaller and more agile ones like deer. Hence, Smilodon could have been too specialized at hunting large prey and may have been unable to adapt.[49] A 2012 study of Smilodon tooth wear found no evidence that they were limited by food resources.[83] Other explanations include climate change and competition with humans[83] (who entered the Americas around the time Smilodon disappeared), or a combination of several factors, all of which apply to the general Pleistocene extinction event, rather than specifically to the extinction of the saber-toothed cats.[84]
Despite the colloquial name "saber-toothed tiger", Smilodon is not closely related to the modern tiger (which belongs in the subfamily Pantherinae), or any other extant felid.[19] A 1992 ancient DNA analysis suggested that Smilodon should be grouped with modern cats (subfamilies Felinae and Pantherinae).[20] A 2005 study found that Smilodon belonged to a separate lineage.[21] A study published in 2006 confirmed this, showing that the Machairodontinae diverged early from the ancestors of modern cats and were not closely related to any living species.[22] The following cladogram based on fossils and DNA analysis shows the placement of Smilodon among extinct and extant felids, after Rincón and colleagues, 2011:[16]
 is Ryubee's beloved pet blue British Shorthair, named by his son Raito (Philip). Despite being a cat, the Smilodon Memory can transform Mick into the humanoid that can discharge electricity and move at blinding speeds, fast enough to evade the homing shots of Kamen Rider Double LunaTrigger and outmaneuver Kamen Rider Accel Trial. He appears to be more intelligent than the average house cat, in that he appears to know that he is able to transform into the Smilodon Dopant and he knows how to transform back into a house cat at will. He is often utilized by the Sonozaki Family to deal with matters outside their estate, such as hunting down Philip and traitors, as well as bodyguard and spy. Mick also appears to favor Wakana over the other members of the family though will faithfully follow Ryubee's orders. While targeting Kyoko, the Smilodon Dopant defeats Accel Trial before Double CycloneMetal catches the cat off guard before destroying his Gaia Driver and Smilodon Memory with the Metal Stag Break Maximum Drive. After Ryubee's death, Mick is brought to live at the Narumi Detective Agency.
Another argument for sociality is based on the healed injuries in several Smilodon fossils, which would suggest that the animals needed others to provide it food.[64] This argument has been questioned, as cats can recover quickly from even severe bone damage and an injured Smilodon could survive if it had access to water.[65] The brain of Smilodon was relatively small compared to other cat species. Some researchers have argued that Smilodon's brain would have been too small for it to have been a social animal.[66] An analysis of brain size in living big cats found no correlation between brain size and sociality.[67] Another argument against Smilodon being social is that being an ambush hunter in closed habitat would likely have made group-living unnecessary, as in most modern cats.[65] Yet it has also been proposed that being the largest predator in an environment comparable to the savanna of Africa, Smilodon may have had a social structure similar to modern lions, which possibly live in groups primarily to defend optimal territory from other lions (lions are the only social big cats today).[45]
The question of sociality is still controversial. Strong support for the traditional concept of a solitary Smilodon is found in its brain. Most social predators, including humans, grey wolves, and lions, have brains that are slightly larger than those of their loner relatives. Smilodon had a relatively small brain, suggesting less ability for complex cooperative behaviors, such as hunting in groups.[43] The high numbers of Smilodon in the tar pits is often dismissed as evidence for a social nature because the golden eagle, a species still extant, is solitary and yet is found in the pits in similar numbers. The social grey wolf and coyote lived in the region, but their fossils in the pits are rare.
Radiocarbon analysis of human remains from the cave returned dates of 2390+/-145 B.P. and 1690+/-115 B.P. These remains were collected from an upper zone approximately 16-feet above the saber-tooth bones. The human remains are believed to be from the Woodland Period and originated thousands of years after the "Smilodon" find. According to Guilday (1977), collagen from the "Smilodon" remains returned radiocarbon dates of 9410+/-155 B.P. and 10,035+/-650 B.P. These dates are extremely late for the presence of "Smilodon" in the Southeast, both contemporaneous with the Dalton horizon and overlapping Paleoindian occupations along the Cumberland River by at least 1,000 years. As such, the dates for the "Smilodon" remains from the First American site should be regarded with some skepticism.
Smilodon was around the size of modern big cats, but was more robustly built. It had a reduced lumbar region, high scapula, short tail, and broad limbs with relatively short feet.[23][24] Smilodon is most famous for its relatively long canine teeth, which are the longest found in the saber-toothed cats, at about 28cm (11in) long in the largest species, S. populator.[23] The canines were slender and had fine serrations on the front and back side.[25] The skull was robustly proportioned and the muzzle was short and broad. The cheek bones (zygomata) were deep and widely arched, the sagittal crest was prominent, and the frontal region was slightly convex. The mandible had a flange on each side of the front. The upper incisors were large, sharp, and slanted forwards. There was a diastema (gap) between the incisors and molars of the mandible. The lower incisors were broad, recurved, and placed in a straight line across. The p3 premolar tooth of the mandible was present in most early specimens, but lost in later specimens; it was only present in 6% of the La Brea sample.[3] There is some dispute over whether Smilodon was sexually dimorphic. Some studies of S. fatalis fossils have found little difference between the sexes.[26][27] Conversely, a 2012 study found that, while fossils of S. fatalis show less variation in size among individuals than modern Panthera, they do appear to show the same difference between the sexes in some traits.[28]