The mandible had a flange on each side of the front. [40] 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. 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. [14] 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. [23] It probably lived in closed habitat such as forest or bush. Subscribe to America's largest dictionary and get thousands more definitions and advanced searchad free! The two subadult individuals uncovered share a unique inherited trait in their dentaries, suggesting they were siblings; a rare instance of familial relationships being found in the fossil record. [4] Members of Smilodontini are defined by their long slender canines with fine to no serrations, whereas Homotherini are typified by shorter, broad, and more flattened canines, with coarser serrations. [8] Smilodon probably avoided eating bone and would have left enough food for scavengers. It had a reduced lumbar region, high scapula, short tail, and broad limbs with relatively short feet. He stated it would have matched the largest modern predators in size, and was more robust than any modern cat. 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. [14] Members of Metailurini were less specialized and had shorter, less flattened canines, and are not recognized as members of Machairodontinae by some researchers. [76], A set of three associated skeletons of S. fatalis found in Ecuador and described in 2021 by Reynolds, Seymour, and Evans suggests that there was prolonged parental care in Smilodon. [83] Examinations by Reynolds, Seymour, and Evans (2021) suggest that Smilodon had a unique and fast growth rate similar to a tiger, but that there was a prolonged period of growth in the genus similar to what is seen in lions, and that the cubs were reliant on their parents until this growth period ended. [4] Based on mitochondrial DNA sequences extracted from fossils, the lineages of Homotherium and Smilodon are estimated to have diverged about 18 Ma ago. Bikini, bourbon, and badminton were places first. [4], 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. [52] A 2012 study of Smilodon tooth wear found no evidence that they were limited by food resources. [19] A 1992 ancient DNA analysis suggested that Smilodon should be grouped with modern cats (subfamilies Felinae and Pantherinae). [74] 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. The two would therefore have held distinct ecological niches. [54] 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. 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. [95], The latest Smilodon fatalis specimen recovered from the Rancho La Brea tar pits has been dated to 13,025 years ago. The cheek bones (zygomata) were deep and widely arched, the sagittal crest was prominent, and the frontal region was slightly convex. populator. Some studies of S. fatalis fossils have found little difference between the sexes. Juvenile and adolescent Smilodon specimens are extremely rare at Rancho La Brea, where the study was performed, indicating that they remained hidden or at denning sites during hunts, and depended on parental care while their canines were developing. [3] There is some dispute over whether Smilodon was sexually dimorphic. [55] The mandibular flanges may have helped resist bending forces when the mandible was pulled against the hide of a prey animal. [49] 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. The curve is similar to that for modern cats such as tigers and cougars, but shifts more towards the robust direction of the axes than is seen in modern felids. 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 hundreds of individuals obtained from the La Brea Tar Pits in Los Angeles constitute the largest collection of Smilodon fossils. [17][14] S.fatalis existed 1.6 million10,000 years ago (late Irvingtonian to Rancholabrean ages), and replaced S.gracilis in North America. A study of postnatal limb bone allometry in felids from the Pleistocene of Rancho La Brea", "Patterns of paravertebral ossification in the prehistoric saber-toothed cat", "Cats in the forest: predicting habitat adaptations from humerus morphometry in extant and fossil Felidae (Carnivora)", "Dental microwear textures of carnivorans from the La Brea Tar Pits, California and potential extinction implications", "Saber-toothed cats were the lions of prehistoric South America", "Implications of diet for the extinction of saber-toothed cats and American lions", "New evidence of the sabertooth cat Smilodon (Carnivora: Machairodontinae) in the late Pleistocene of southern Chilean Patagonia", "Two New Studies of Sabertooth (Smilodon fatalis) Anatomy", "Sudden Deaths: The Chronology of Terminal Pleistocene Megafaunal Extinction", Faceted Application of Subject Terminology, https://en.wikipedia.org/w/index.php?title=Smilodon&oldid=1099134178, Wikipedia pending changes protected pages, Short description is different from Wikidata, All Wikipedia articles written in American English, Articles containing Ancient Greek (to 1453)-language text, Pages using multiple image with auto scaled images, Creative Commons Attribution-ShareAlike License 3.0, This page was last edited on 19 July 2022, at 05:00. [96] [42] The availability of prey in the Rancho La Brea area was likely comparable to modern East Africa. [84] One study of 1,000 Smilodon skulls found that 36% of them had eroded parietal bones, which is where the largest jaw muscles attach. 2022. Animals were accidentally trapped in the seeps and became bait for predators that came to scavenge, but these were then trapped themselves. [65], The Talara Tar Seeps in Peru represent a similar scenario, and have also produced fossils of Smilodon. [35] 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. ZOE CHAMBERLAIN TAKES A TRIP BACK IN TIME, An excavation reveals cats' 500-lb. The genus was named in 1842 based on fossils from Brazil; the generic name means "scalpel" or "two-edged knife" combined with "tooth". If caused by intraspecific fighting, it may also indicate that they had social behavior which could lead to death, as seen in some modern felines (as well as indicating that the canines could penetrate bone). [47] 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. [33] This is larger than tracks of the Bengal tiger, to which the footprints have been compared. [1] S.fatalis has junior synonyms such as S.mercerii, S.floridanus, and S. Traditionally, the most popular theory is that the cat delivered a deep stabbing bite or open-jawed stabbing thrust to the throat, killing the prey very quickly. This analysis of its diet also indicates that S. populator hunted both in open and forested habitats. Its jaw had a bigger gape than that of modern cats, and its upper canines were slender and fragile, being adapted for precision killing. [14], S.populator was very successful, while Homotherium never became widespread in South America. [52][53] Another hypothesis suggests that Smilodon targeted the belly of its prey. After Smilodon reached 23 to 30 months of age, the infant teeth were shed while the adult canines grew at an average growth rate of 7mm (0.3in) per month during a 12-month period. One study of African predators found that social predators like lions and spotted hyenas respond more to the distress calls of prey than solitary species. 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. The term "saber-tooth" refers to an ecomorph consisting of various groups of extinct predatory synapsids (mammals and close relatives), which convergently evolved extremely long maxillary canines, as well as adaptations to the skull and skeleton related to their use. Many of the carnivores at Talara were juveniles, possibly indicating that inexperienced and less fit animals had a greater chance of being trapped.
[47], Whether Smilodon was sexually dimorphic has implications for its reproductive behavior. The discovery, made by Figueirido and Lautenschlager et al., published in 2020 suggests extremely different ecological adaptations in both machairodonts. [4] The skull and mandible morphology of the earliest saber-toothed cats was similar to that of the modern clouded leopards (Neofelis). [75] It has been suggested that the exaggerated canines of saber-toothed cats evolved for sexual display and competition, but a statistical study of the correlation between canine and body size in S. populator found no difference in scaling between body and canine size concluded it was more likely they evolved solely for a predatory function. [51], The heel bone of Smilodon was fairly long, which suggests it was a good jumper. [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. The best-known of such traps are at La Brea in Los Angeles, which have produced over 166,000 Smilodon fatalis specimens[64] that form the largest collection in the world. [4][8] Large tracks from Argentina (for which the ichnotaxon name Smilodonichium has been proposed) have been attributed to S. populator, and measure 17.6cm (6.9in) by 19.2cm (7.6in). [43], 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.
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. fatalis. [15] As their canines became longer, the bodies of the cats became more robust for immobilizing prey. S.fatalis had a weight of 160 to 280kg (350 to 620lb) and height of 100cm (39in).
All content on this website, including dictionary, thesaurus, literature, geography, and other reference data is for informational purposes only. Smilodon lived in the Americas during the Pleistocene epoch (2.5 mya 10,000 years ago). [95], Writers of the first half of the twentieth century theorized that the last saber-toothed cats, Smilodon and Homotherium, became extinct through competition with the faster and more generalized felids that replaced them. Smilodon remains exhibit relatively more shoulder and lumbar vertebrae injuries. [41] Isotopic studies of dire wolf (Aenocyon dirus) and American lion (Panthera atrox) bones show an overlap with S.fatalis in prey, which suggests that they were competitors. [91] The American interchange resulted in a mix of native and invasive species sharing the prairies and woodlands in South America; North American herbivores included proboscideans, horses, camelids and deer, South American herbivores included toxodonts, litopterns, ground sloths, and glyptodonts. He referred the specimen to the genus Felis (which was then used for most cats, extant as well as extinct) but found it distinct enough to be part of its own subgenus, as F. (Trucifelis) fatalis. [3] Nordic paleontologists Bjrn Kurtn and Lars Werdelin supported the distinctness of the two species in an article published in 1990. [45] Smilodon itself may have scavenged dire wolf kills. 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. 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. North America also supported other saber-toothed cats, such as Homotherium and Xenosmilus, as well as other large carnivores including dire wolves, short-faced bear (Arctodus simus) and the American lion. [77], Several Smilodon fossils show signs of ankylosing spondylitis, hyperostosis and trauma. [31] A particularly large S. populator skull from Uruguay measuring 39cm (15in) in length indicates this individual may have weighed as much as 436kg (961lb). fatalis. [1][13] Within the family Felidae (true cats), members of the subfamily Machairodontinae are referred to as saber-toothed cats, and this group is itself divided into three tribes: Metailurini (false saber-tooths); Homotherini (scimitar-toothed cats); and Smilodontini (dirk-toothed cats), to which Smilodon belongs. populator. If correctly identified, the tracks indicate that the animal had fully retractible claws, plantigrade feet, lacked strong supination capabilities in its paws, notably robust forelimbs compared to the hindlimbs, and was probably an ambush predator. [85] 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. This and comparisons with bite marks left by the contemporary machairodont Xenosmilus suggest that Smilodon and its relatives could efficiently de-flesh a carcass of meat when feeding without being hindered by their long canines. [66] One critical study claims that the study neglects other factors, such as body mass (heavier animals are more likely to get stuck than lighter ones), intelligence (some social animals, like the American lion, may have avoided the tar because they were better able to recognize the hazard), lack of visual and olfactory lures, the type of audio lure, and the length of the distress calls (the actual distress calls of the trapped prey animals would have lasted longer than the calls used in the study). [47], 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. [32] It stood at a shoulder height of 120cm (47in). This may have been focused more towards competition such as other Smilodon or potential threats such as other carnivores than on prey. [86], Smilodon lived during the Pleistocene epoch (2.5 mya10,000 years ago), and was perhaps the most recent of the saber-toothed cats. [14] Isotopic analysis for Smilodon populator suggests that its main prey species included Toxodon platensis, Pachyarmatherium, Holmesina, species of the genus Panochthus, Palaeolama, Catonyx, Equus neogeus, and the crocodilian Caiman latirostris. [80][81][82], A 2017 study indicates that juveniles were born with a robust build similar to the adults. populator. S.populator from South America was the largest species, at 220 to 436kg (485 to 961lb) in weight and 120cm (47in) in height, and was among the largest known felids.
Comparison of the bones of juvenile S. fatalis specimens from La Brea with those of the contemporaneous American lion revealed that the two cats shared a similar growth curve. [50], Debate continues as to how Smilodon killed its prey. [39] Some coat features, such as the manes of male lions or the stripes of the tiger, are too unusual to predict from fossils. [77] The structure of the hyoid bones suggest that Smilodon could roar like modern big cats, which may have implications for their social life. The fact that saber-teeth evolved many times in unrelated lineages also attests to the success of this feature.
[30] It was similar to a lion in dimensions, but was more robust and muscular, and therefore had a larger body mass. The thickening of S.fatalis femurs was within the range of extant felids. [65], Scientists debate whether Smilodon was social. Sternum injuries are also common, probably due to collision with prey. Its extinction has been linked to the decline and extinction of large herbivores, which were replaced by smaller and more agile ones like deer. 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. You must there are over 200,000 words in our free online dictionary, but you are looking for one thats only in the Merriam-Webster Unabridged Dictionary. The species was based on a partial canine, which had been obtained in the Port Kennedy Cave near the Schuylkill River in Pennsylvania. This may have been because the layers were shallower, so the thrashing of trapped animals damaged the bones of previously trapped animals. Cope found the canine to be distinct from that of the other Smilodon species due to its smaller size and more compressed base. [23] The canines were slender and had fine serrations on the front and back side. [8] S.populator existed 1 million10,000 years ago (Ensenadan to Lujanian ages); it occurred in the eastern parts of South America. [8][17][23] However, in 2018, a skull of S.fatalis found in Uruguay east of the Andes was reported, which puts the idea that the two species were allopatric (geographically separated) into question. The sediments of the pits there were accumulated 40,000 to 10,000 years ago, in the Late Pleistocene. Though Lund thought accumulations of Smilodon and herbivore fossils in the Lagoa Santa Caves were due to the cats using the caves as dens, these are probably the result of animals dying on the surface, and water currents subsequently dragging their bones to the floor of the cave, but some individuals may also have died after becoming lost in the caves. The subadults were estimated to have been around two years of age at the time of their deaths, but were still growing. [90], S. gracilis entered South America during the early to middle Pleistocene, where it probably gave rise to S.populator, which lived in the eastern part of the continent. [44] The differences between the North and South American species may be due to the difference in prey between the two continents. [11] S.gracilis has at times been considered part of genera such as Megantereon and Ischyrosmilus. It was similar to its predecessor Megantereon of the same size, but its dentition and skull were more advanced, approaching S. [73] An analysis of brain size in living big cats found no correlation between brain size and sociality. [25] The skull was robustly proportioned and the muzzle was short and broad. [37] Antn 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. 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. [92][93], Along with most of the Pleistocene megafauna, Smilodon became extinct 10,000 years ago in the Quaternary extinction event. Accessed 21 Jul. Homotherium differs from the more widely known saber-toothed tiger, (2003) analyzed the presence of bone pathology in the extinct mammalian predator, En menor medida se reporta la ocurrencia de carnivoros: Canidae (Theriodictis, Protocyon y Dusicyon avus), Felidae (, As part of inktank's school holiday activities, children can see replicas and fossils of many creatures including the sabre-toothed tiger, The mountain lion is one of the most recently evolved felids, a New World species that at its beginnings shared the landscape with dire wolves, carnivorous short-faced bears, and the terrifying, Dictionary, Encyclopedia and Thesaurus - The Free Dictionary, the webmaster's page for free fun content, Bite-sized day out; Chester Zoo UNVEILS WORLD EXCLUSIVE Predators exhibition, Hunter thrillers; HUGE ANIMATRONIC PREDATORS ON SHOW IN ZOO'S LATEST ATTRACTION, Top 10; Take a look at our pick of the best shows on the small screen this week, Simply the beast; WEST MIDLAND SAFARI PARK'S NEW PS1.25 MILLION ICE CAVE ATTRACTION IS WOWING VISITORS DURING THE EASTER HOLIDAYS.