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Post by brobear on May 7, 2017 5:14:17 GMT -5
Smilodon musculature:
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Post by brobear on May 7, 2017 5:26:45 GMT -5
I had began discussing "Smilodon" under the topic "Pleistocene Grizzly" but I have decided that this discussion deserves it's own page. First posted by Tigerluver ( biologist ). wildfact.com/forum/ Smilodon populator - A new fossil and questions about bone robusticity to cursoriality, among other issues Browsing through some older document, I found one of great insight to Smilodon fatalis and S. populator morphology, Relationships between North and South American Smilodon by Björn Kurtén and Lars Werdelin. The differences between the forms were analyzed by this work, and you can read up on it in the attachment. Postcranial anatomy interests me the most. For one, I found a record size humerus of 410 mm. Isometrically comparing to the bear humerus of 400.5 mm, this specimen would be about 470 kg (a post on p. 1 explains why bears may be better isometric basis for this species). This humerus puts S. populator back at the top of felid weights. But there's a caveat. The same document found that "the forelimb of S. populator is somewhat longer, relative to the hindlimb, than in S. fatalis. Such a lengthening of the forelimb is a characteristic of the open plains." An example of this observation is the fact that lion has a proportionally longer humerus and ulna compared to the hindlimb bones, being the only big cat living almost exclusively in the open plains. This morphological characteristic results in overestimation of mass from all bone measurements when comparing to a more average proportional individual. Bone length overestimates because the bone is disproportionately long, and width dimensions overestimate because the width is more for accommodating running stress than muscle in such cases. The brown bear has much shorter frontlimbs than hindlimbs are compared to S. populator, and a bit shorter proportions compared to S. fatalis. In this form, S. fatalis is more robust and bear-like than S. populator, but neither were probably as muscular as a bear, but rather some of the bone width was more for running stress similarly to how lions bones have widened so greatly as compared to other cats. With that, the S. populator estimation using the brown bear as the base is probably an overestimate, or faulty at the least. S. fatalis reconstructions from a brown bear may be a bit less of an overestimate. Smilodon would lack the posterior weight the bear would in the this areas due to the FL/HL discrepancy, and thus the two species are not analogous, at least for humerus calculations. It is very possible the opposite effects of mass estimation would occur if a brown bear femur is being compared to the proportionately shorter Smilodon femur. Smilodon's femur is proportionately much larger than its tibia compared to all pantherines by a long ways. Its humerus is also proportionately larger than its ulna, a ratio only matched by the very robust leopard and jaguar. The longer proximal bones is indicative of the fact that Smilodon is indeed much more heavily built than the lion and the tiger, and somewhat more heavyset than the leopard and jaguar. From this, maybe the best route of Smilodon reconstruction would be one width dimensions and/or the length dimension of the bone, either allometrically or isometrically compared to only jaguars and leopards. The type of bone being used would also have to be taken into account to predict the accuracy of the estimation. Forelimb estimates may be overestimates somewhat, and vice versa for hindlimb estimates.
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Post by brobear on May 7, 2017 5:33:09 GMT -5
www.ucmp.berkeley.edu/mammal/carnivora/sabretooth.html The "saber-toothed tiger," Smilodon, is the California State Fossil and the second most common fossil mammal found in the La Brea tar pits. The name "saber-toothed tiger" is misleading as these animals are not closely related to tigers. Juvenile to adult-sized fossils are represented in the large Berkeley collections. The first Chairman of the University of California Department of Paleontology, Professor John C. Merriam, and his student Chester Stock, monographed the morphology of this great carnivore in 1932. Since then, hundreds of thousands of Smilodon bones have been found at La Brea. These finds have permitted remarkably detailed reconstructions of how Smilodon lived. We now know Smilodon was about a foot shorter than living lions but was nearly twice as heavy. Also, unlike cheetahs and lions (which have long tails that help provide balance when the animals run) Smilodon had a bobtail. These suggest that Smilodon did not chase down prey animals over long distances as lions, leopards, and cheetahs do. Instead, it probably charged from ambush, waiting for its prey to come close before attacking. Smilodon is a relatively recent sabertooth, from the Late Pleistocene. It went extinct about 10,000 years ago. Fossils have been found all over North America and Europe. Smilodon fossils from the La Brea tar pits include bones that show evidence of serious crushing or fracture injuries, or crippling arthritis and other degenerative diseases. Such problems would have been debilitating for the wounded animals. Yet many of these bones show extensive healing and regrowth indicating that even crippled animals survived for some time after their injuries. How did they survive? It seems most likely that they were cared for, or at least allowed to feed, by other saber-toothed cats. Solitary hunters with crippling injuries would not be expected to live long enough for the bones to heal. Smilodon appears to have lived in packs and had a social structure like modern lions. They were unlike tigers and all other living cats, which are solitary hunters. Occasional finds of sabertooth-sized holes in Smilodon bones suggest the social life of Smilodon was not always peaceful. The cats may have fought over food or mates as lions do today. Such fights were probably accompanied by loud roaring. From the structure of the hyoid bones in the throat of Smilodon, we know it could roar.
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Post by brobear on May 7, 2017 7:07:02 GMT -5
Smilodon was an extremely muscular big cat. Much more so than a lion or a tiger. However, when you look at him from above you can see that, just as with all cats, he has a narrow body. The body of a bear is broader, thicker, and more "square-shaped" which is clearly a more sturdy body-plan.
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Post by brobear on May 8, 2017 3:14:58 GMT -5
library.sandiegozoo.org/factsheets/_extinct/smilodon/smilodon.htm
Estimated Body Weight: Smilodon fatalis: 160-280 kg (353-617 lb) Smilodon gracilis: 55-100 kg (121-221 lb) Smilodon populator: Up to 400 kg (882 lb) Body Length: Smilodon fatalis: 175 cm (68.9 in) (measured rump to snout) Height at Shoulder: Smilodon fatalis: 100 cm (39.37 in) Tail Length: Smilodon fatalis: 35 cm (13.8 in) *According to the scant fossil record of the Pleistocene grizzly, these bears were very likely normally within the same size range as Smilodon Fatalis. One-on-one, we are looking at a size-parity fight. However, the fossil record strongly suggests that the saber-toothed cats were most likely social predators similar to modern lions. For this reason, the grizzly probably avoided them.
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Post by brobear on May 8, 2017 7:36:09 GMT -5
cenozoiclife.blogspot.com/2015/04/scimitar-cat-homotherium-serum.html Scimitar Cat (Homotherium serum) The Scimitar Cat (Homotherium serum) was a smaller and lesser known cousin of the more famous Saber-toothed Cat (Smilodon fatalis). This species lived from the early Pliocene to the late Pleistocene and enjoyed one of the largest geographic distributions of any known cat living or extinct. The genus name Homotherium is derived from the Greek words homo, meaning “same”, and therion, meaning “beast”. The common name “Scimitar-toothed Cat” or “Scimitar Cat” is in reference to this cat’s blade-like canines, named after the curved sword from southwest Asia. Numerous species have been attributed to the genus based on body size, the shape of the canines, and geographic location. However, these supposed differences are minor and may be attributed to sexual and geographic variation. It must be noted that such fluctuations may easily be observed among modern cats which have particularly broad distributions. Here, I will be focusing on the North American variant of this genus, Homotherium serum. Scimitar Cats had an extremely wide distribution that encompassed Africa, Eurasia, North America, and South America. This nearly global distribution was matched only by the Lion (Panthera leo) among contemporary felids. The Scimitar Cat’s preferred habitat would have been grassland, open woodland, and semi-desert. This species seems to have originated in Eurasia about 5mya during the early Pliocene, is recorded in Africa by 3mya, North America by the start of the Pleistocene, and reached South American pampas by at least 1.8mya. The extinction of Scimitar Cats around the world seems to coincide with the disappearance of many of the larger herbivores within its range. The youngest evidence for the species in North America is about 11,000 years old. Compared to comparably-sized cats of the Pleistocene, Scimitar Cats were much more lightly built and rangy in their overall body proportions. They were particularly well-adapted for covering great distances of open terrain at considerable speeds. Cursorial* adaptations include; long slender limbs to increase its stride, a deep thoracic cavity that housed a large heart and lungs, large nasal passages for high oxygen intake, a short lower back to save energy when running, and non-retractile claws for traction. The forelimbs were slightly longer than the hindlimbs. Scimitar Cats were built for long-distance pursuit rather than power, likely adopting a tireless cantering gait when running. As a cat of the open plains, its coat is likely to have been either mostly plain or spotted, the background color varying with region. In temperate zones, a light summer coat would likely have given way to a thicker, darker-colored winter coat. The cats’ most impressive feature was its highly sectoral* dentition. All the teeth were lined with fine serrations on their front and back edges. The upper canines were up to 15cm (6in) long and blade-shaped. These killing teeth were well-suited for slicing through thick hide and severing blood vessels of large prey items. Large incisors were adept at gripping prey and dismembering carcasses. The carnassials* were extremely well-developed relative to contemporary cats and would have enabled Scimitar Cats to cut away steak-sized chunks of flesh with every bite. Among living cats only the Cheetah (Acinonyx jubatus) has such efficient meat slicing teeth, which are adapted for speedily devouring their prey on the competitor-rich plains in which they live. Much of what we know about the Scimitar Cat comes from the wealth of fossil materials unearthed from Friesenhahn Cave, Texas. Prior to the discovery of this site, Scimitar Cats were known only from very fragmentary remains elsewhere in the world. Once an active den site for these animals, this famous locality has yielded the remains of at least 32 individuals (19 adults and 13 cubs), providing unparalleled insight into the ontology, ecology, and behavior of these cats. The following description will be based on inferences made by the Friesenhahn sample. The disarticulated remains of large herbivores such as bison, horse, mammoth, mastodon, camel, deer, and tapir indicate that Scimitar Cats enjoyed a wide prey menu consisting of animals weighing 300 to 1,000kg. By far the most notable aspect of this cave fauna, however, are the bones and teeth of several hundred juvenile Columbian Mammoths (Mammuthus columbi) and some American Mastodon (Mammut americanum). The young elephants were determined to have been between 2 and 4 years of age around the time of death. This is the same age at which modern elephant calves become less dependent on their mothers and their curiosity occasionally compels them to stray dangerously far from the protective adults. Thus, this is the period during which they are most vulnerable to attack from predators. Lions today will take full advantage of this behavior and opportunistically hunt these stray calves. Scimitar Cats, it seems, were doing the same thing with the mammoth and mastodon calves from the Friesenhahn locality. The great size of the animals that Scimitar Cats were hunting also tells us something about its social life. Averaging about the weight of a Lioness and more slender in build, Scimitar Cats would have found it rather difficult, if not impossible, to tackle such large prey single-handed, particularly the larger bison and elephant calves found at Friesenhahn. Thus, these cats most likely lived and hunted in groups. It can even be suggested that the Scimitar Cats at Friesenhahn represent a single family lineage that utilized the cave and surrounding area over successive generations as modern Lions are known to do. The cave would have been used as a shelter during the dry season and a safe environment in which to leave their cubs while hunting. It also offered a permanent supply of water. The cave would have been abandoned during the wetter periods of the year from May to October due to flooding. The home ranges of Scimitar Cats are likely to have been quite large and the cats would have been highly nomadic within this area. Seasonal movements depended on the migratory habits of local prey. As a result, the species had a relatively small population density compared to other large predators of the time. Unlike other cats, Scimitar Cats were built for long-distance pursuit rather than ambush. Hunting techniques would have varied according to the type of prey, but in general these predators would have isolated and chased down intended victims, seizing them by the rump or hindquarters with enlarged dewclaws* in order to prevent escape. Other pack members would have then attacked the hindlimbs and throat of the immobilized prey, severing tendons and blood vessels with their blade-like teeth. The prey would have been killed rather quickly rapid blood loss. Kills would then be torn apart and eaten as rapidly as possible before competing predators could arrive on the scene. Powerful shoulders allowed Scimitar Cats to lift and carry away large pieces of surplus meat over long distances to a safe place to be consumed at a later date or fed to den-bound cubs.
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Post by brobear on May 8, 2017 7:38:17 GMT -5
prehistoric-fauna.com/Homotherium-serum 10 reviews Homotherium serum (Dinobastis serus Cope 1893) Order: Carnivora Family: Felidae Subfamily: †Machairodontinae Tribe: †Homotherini Size: 2.1 m ( 7 feet ) in length, 110 cm ( 3 feet 7 inches ) in height, 150 - 230 kg ( 330 to 507 pounds ) of weight. Time period: from the late Pliocene until the late Pleistocene (North America) In North America, Homotherium serum occurred from the late Pliocene until the late Pleistocene. Remains have been found at various sites between Alaska and Texas. The scimitar cat is about the size of a lion, but lighter in body. The unusually large, square nasal opening, like that of the cheetah, presumably allows quicker oxygen intake aiding in rapid running and cooling the brain. As in the cheetah too, the brain's visual cortex is large and complex, emphasizing the scimitar cat's ability to see well and function in the day, rather than the night, as in most cats. The rest of the skeleton suggests that H. serum is built for short bursts of speed, as well as agility. The broad "wings" of the atlas (first neck vertebra) help to support the massive muscles used to depress the head to inflict a killing bite. The pelvic region, including the sacral vertebrae, are bear-like, as is the short tail composed of 13 vertebrae about half the number in long-tailed cats. Such features suggest ambushing of prey and short chases. Its relatively slender bones indicates a lighter body with more flexibility in running than sabretooths and lions. Like the cheetah, H. serum sacrificed retractile claws for better running traction. Features of the hindlimbs indicate that this cat was moderately capable of leaping. Hindlimbs are short relative to the forelimbs, and have bear-like heel and ankle bones. Taken together, these features indicate a semiplantigrade stance, the hindlimbs being between that of a bear (plantigrade, or walking on the sole of the foot like humans) and that of a lion (digitigrade, or walking on the toes). Its stance at rest may have been slightly hyena-like with sloping hindquarters. Perhaps the top speed of the scimitar cat would have been greater than a bear and approaching a lion about 60 km/hour. According to relationships between thigh bone (femur) measurements and body weights of large carnivores, H. serum may have weighed about 230 kg in the lion range.
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Post by brobear on May 8, 2017 7:53:37 GMT -5
Depending on the individual animals, the scimitar cat was roughly within the size range of the grizzly. Probably a loner although there is the possibility that they hunted in small groups. It is doubtful that these light-weight predators targeted adult bears as potential prey.
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Post by Polar on May 19, 2017 0:36:35 GMT -5
Homotherium most likely would not have had run-ins with the grizzly--but with the Arctodus instead.
It is important to note that grizzlies lived more north and towards the coasts than in the inner plains (plenty of competition there), so that they could avoid potential conflict as much as possible.
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Post by brobear on May 19, 2017 15:38:15 GMT -5
Homotherium most likely would not have had run-ins with the grizzly--but with the Arctodus instead. It is important to note that grizzlies lived more north and towards the coasts than in the inner plains (plenty of competition there), so that they could avoid potential conflict as much as possible. I would think that grizzlies were much more scarce out on the plains, which, by the way, were more wooded and with lusher vegetation than our modern prairie. They were likely more heavily populated in mountainous terrain and forested areas. However, biologists who study grizzly behavior believe that their "grizzly disposition" is inherited from a bear that once lived in open country where he had to cope with a multitude of large predators. I guess we will never know for sure just how they were populated because with such a heavy population of predators and scavengers, bones had little chance of being preserved. The short-faced bear was a monster that the grizzly certainly avoided. Panthera atrox was a huge predator too. One-on-one against a full-grown male grizzly was not a fight that this or any other big cat would have sought, but she-bears and juveniles would have lived in constant peril. I don't believe that a grizzly would have challenged an atrox either. The one other predator that a full-grown boar grizzly would have avoided was Smilodon; who hunted in prides like lions. One paleontologist once said that in Europe, where the giant vegan cave bear lived, the grizzlies were highly carnivorous. In North America, where the giant short-faced bear lived, the grizzlies were highly vegetarian. - Just a theory.
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Post by brobear on Jan 2, 2018 4:34:48 GMT -5
Some new info: Saber-toothed cat vs grizzly one-on-one. Despite the popular claim that the saber-tooth was pound-for-pound stronger than a grizzly, in truth it is the great bear who holds the advantage in overall brute strength. Although in this case only a slight advantage. Likewise, in having a physique more bear-like than cat-like, the saber-tooth has forsaken speed and agility for muscle. Therefore this big cat's advantages of speed and agility are also minimal. As for size, here again these two adversaries are pretty near size parity. So, in a face-to-face confrontation who would be the champion? Average Smildon: Shoulder height: 3 feet 3 inches. Body Length: 5 feet 11 inches. Weight: 600 pounds. Average grizzly: Shoulder height: 4 feet Body Length: 8 feet. Weight: from 600 to 800 pounds.
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Post by Deleted on Jan 2, 2018 9:18:55 GMT -5
Another comparison: Grizzly bear vs Smilodon fatalis.
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Post by brobear on Jan 2, 2018 11:50:55 GMT -5
Well done! Beautiful Gurahl. This would be the fight of the ages! Anything could happen. I would bet on the grizzly; but only because of favoritism. I would not bet too heavily.
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Post by brobear on Jan 10, 2018 19:10:09 GMT -5
I honestly believe this face-off to be a draw. With a full-grown male of each species in a face-off confrontation, anything could happen. The bear has a slim strength advantage while the big cat has a slim advantage in speed and agility. Much of its cat-like abilities were traded off for brute strength. They are very near size parity. I would make a small wager on the grizzly and, while I'm cheering for him, my confidence would not be very high. A 50-50 chance of wining is like flipping a coin. Heads you loose; tails you win. In the wilderness of Pleistocene N. America, the mature grizzly boar and the adult male saber-toothed cat probably avoided each other.
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Post by brobear on Jan 11, 2018 4:31:52 GMT -5
www.livescience.com/5166-sabertooth-tigers-social-beasts.html Leopards and tigers today are fairly solitary beasts, but the extinct sabertooth cat was likely a social animal that lived and hunted like today’s lions, a new study suggests. The sabertooth cat (Smilodon fatalis) is famous for its extremely long canine teeth, which reached up to seven inches in length and extended below the lower jaw. Although commonly called the "sabertoothed tiger," the species is actually not closely related to the tiger, which is part of a different subfamily. However, the sabertooth cat was large and muscular, similar in size to a modern-day tiger. Scientists from UCLA and the Zoological Society of London concluded that the sabertooth cat was social by using a novel technique: They compared numbers of present-day carnivores competing for kills in Africa with those of mainly extinct species found in a North American fossil deposit. Smilodon lived in North and South America between 1.8 million and 10,000 years ago and is one of the most common species preserved at the Rancho La Brea tar pits of Los Angeles, a fossil deposit in which dying herbivores trapped in sticky asphalt attracted numerous dire wolves and sabertooth cats, some of which also died there. Because most living cats are solitary, controversy has persisted over the social life of Smilodon. The study, detailed in the Oct. 28 issue of the journal Biology Letters, involved comparing data from the La Brea fossil record and data obtained from "playbacks" used in Africa, in which the recorded calls of distressed prey and the sounds of lions and hyenas are used to attract carnivores. This technique has been used by scientists to estimate carnivore densities in eastern and southern Africa. The playback results showed that large social species made up a far larger proportion of the animals attracted than one would expect, considering their population size compared to other carnivores. Large social carnivores were, in fact, found to attend about 60 times more often than expected on the basis of relative abundance. When these results were compared with the records at the tar pits, the scientists found that the proportion of Smilodon records matched the proportion of the large social carnivores in the playbacks. "It absolutely makes sense that social species will predominate at carcasses, both now and in the past," said researcher Blaire Van Valkenburgh, UCLA professor of ecology and evolutionary biology. "Why approach a situation where you are likely to encounter dangerous competitors without having a few friends along?" Smilodon lived in North and South America between 1.8 million and 10,000 years ago and is one of the most common species preserved at the Rancho La Brea tar pits of Los Angeles, a fossil deposit in which dying herbivores trapped in sticky asphalt attracted numerous dire wolves and sabertooth cats, some of which also died there. Because most living cats are solitary, controversy has persisted over the social life of Smilodon. The study, detailed in the Oct. 28 issue of the journal Biology Letters, involved comparing data from the La Brea fossil record and data obtained from "playbacks" used in Africa, in which the recorded calls of distressed prey and the sounds of lions and hyenas are used to attract carnivores. This technique has been used by scientists to estimate carnivore densities in eastern and southern Africa. The playback results showed that large social species made up a far larger proportion of the animals attracted than one would expect, considering their population size compared to other carnivores. Large social carnivores were, in fact, found to attend about 60 times more often than expected on the basis of relative abundance. When these results were compared with the records at the tar pits, the scientists found that the proportion of Smilodon records matched the proportion of the large social carnivores in the playbacks. "It absolutely makes sense that social species will predominate at carcasses, both now and in the past," said researcher Blaire Van Valkenburgh, UCLA professor of ecology and evolutionary biology. "Why approach a situation where you are likely to encounter dangerous competitors without having a few friends along?"
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Post by brobear on Jan 11, 2018 4:40:21 GMT -5
One-on-one, a grizzly has as good a chance as the saber-toothed cat of walking away. But, not even the biggest baddest grizzly who ever breathed would dare to challenge or accept the challenge of a pride of saber-toothed cats. As with the giant short-faced bear, the Ice Age grizzly more assuredly took precautions to avoid these savage big cats. I am just as certain that in North Africa, the Atlas bear likewise avoided the big BarBary lions. I wonder if, like lions, did Smilodon also form male-coalitions or was each pride ruled by a single male?
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Post by brobear on Sept 4, 2018 5:21:42 GMT -5
In the 2014 High Plains Book Award winner for Medicine & Science, and his new, substantially revised edition, In the Shadow of the Sabertooth: Global Warming, the Origins of the First Americans and the Terrible Beasts of the Pleistocene, famed wilderness defender Doug Peacock gives the reader a profoundly new look at Ice Age global warming in North America, its effects on human colonization, extinction of the great American megafauna and the crucial survival lessons that can be applied to our rapidly changing climate. For the first time in popular scientific literature, Peacock reports on recent genetic evidence revealing the two Holy Grails of American archaeology: the origins of the First Americans and the Clovis people. Published by CounterPunch and AK Press 2013. Revised edition published 2014. 194 Pages. store.counterpunch.org/product/in-the-shadow-of-the-sabertooth-a-renegade-naturalist-considers-global-warming-the-first-americans-and-the-terrible-beasts-of-the-pleistocene/
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Post by brobear on Sept 5, 2018 6:29:51 GMT -5
today.duke.edu/2009/11/sabertooth.html Despite their fearsome fangs, male sabertoothed cats may have been less aggressive than many of their feline cousins, says a new study of male-female size differences in extinct big cats. Commonly called the sabertoothed tiger, Smilodon fatalis was a large predatory cat that roamed North and South America about 1.6 million to 10,000 years ago, when there was also a prehistoric cat called the American lion. A study appearing in the November 5 issue of the Journal of Zoology examined size differences between sexes of these fearsome felines using subtle clues from bones and teeth. The researchers report that while male American lions were considerably larger than females, male and female sabertoothed cats were indistinguishable in size. The findings suggest that sabertooths may have been less aggressive than their fellow felines, researchers say. In species where males fight for mates, bigger, heavier males have a better chance of winning fights, fending off their rivals and gaining access to females. After generations of male-male competition, the males of some species evolve to be much larger than their mates. Most big cats have a form of sexual dimorphism where males are bigger than females, said co-author Julie Meachen-Samuels, a biologist at the National Evolutionary Synthesis Center in Durham, NC. So she and Wendy Binder of Loyola Marymount University in Los Angeles wanted to know if extinct sabertooths and American lions showed the same size patterns as big cats living today. When it comes to fossils, sorting males from females can be tricky. "It's hard to tell who's a male and who's a female in the fossil record," said Blaire Van Valkenburgh, a biologist at UCLA who has studied these animals extensively but was not an author on the paper. "Unless you're lucky enough to get some DNA, or you're working with an animal where males have horns and females don't." For species that keep growing into adulthood, simply separating the fossils into two groups by size may not do the trick, either. "It's easy to get a younger, smaller male confused with an older, larger female if you're just dividing them by size," Meachen-Samuels said. The researchers accounted for continued growth using subtle clues from fossilized teeth. "Teeth fill in over time," said Binder. "In young animals the tooth cavity is basically hollow, but as they get older it fills in with dentin. It won't give you an exact age, but it can give you a relative age in terms of young, middle aged or old," Binder added. Meachen-Samuels and Binder x-rayed the lower teeth and jaws of 13 American lions and 19 sabertoothed cats recovered from the La Brea Tar Pits in Los Angeles. To account for growth over time, they measured tooth cavity diameter and plotted it against jaw length for each species. Plotted this way, the data for the American lion fell easily into two groups, regardless of age. The researchers concluded that "the little ones were females and the big ones were males," said Van Valkenburgh. In contrast, sabertoothed cat sizes seemed to be governed solely by age. It would appear that the males were indistinguishable from their mates. "Even by incorporating a measure of age, you can't distinguish males and females," said Meachen-Samuels. Size differences between the sexes tend to be more impressive in species where male aggression is more intense, and in the extinct American lion, size differences between the sexes were even more dramatic than in lions living today. The closest living relative of the American lion, "African lions engage in aggressive takeovers where one to several males will take over an entire pride -- the males have battles to the death," said Van Valkenburgh. "Living lions have huge sexual dimorphism," said Meachen-Samuels. Based on their findings, the researchers think the American lion probably lived in male-dominated groups, where 1-2 males monopolized and mated with multiple females. "My guess would be that the American lion was similar to African lions, where males guard groups of females," said Meachen-Samuels. "But we don't see that in the sabertoothed cat," Binder said. The size similarity in sabertoothed cats suggests that male sabertooths may have been less aggressive than their larger cousins. "Rather than males having harems of females, the males and females in a group might have been more equal," Binder said.
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Post by brobear on Sept 8, 2018 8:21:08 GMT -5
Rethinking the ages-old theory ( which was quickly dismissed ) that perhaps Smilodon killed using his saber-canines with his mouth closed; like a walrus which just happens to be the only modern animal living with long canine tusks similar ( in some respects ) to those of the saber-toothed cats. Consider that Smilodon has a weak bite-force but very powerful neck and shoulders which even rival those of a grizzly.
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Post by brobear on Sept 11, 2018 6:20:06 GMT -5
600 pound Smilodon vs 600 pound grizzly... I bet the farm on the bear. There is a theory ( I was going to copy and paste but could not find again ) that Panthera atrox ( American lion ) slowly but surely displaced the saber-toothed cats from N. America.
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