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Post by brobear on Feb 20, 2019 11:13:37 GMT -5
By Taipan: Arctodus simus Arctodus (Greek, "bear tooth") — known as the short-faced bear or bulldog bear — is an extinct genus of bear endemic to North America during the Pleistocene ~3.0 Ma.—11,000 years ago, existing for approximately three million years. Arctodus simus may have once been Earth's largest mammalian, terrestrial carnivore. It was the most common of early North American bears, being most abundant in California. It was native to prehistoric North America from about 800,000 years ago, and became extinct about 12,500 years ago. It has been found from as far north as Ikpikpuk River, Alaska to Lowndes County, Mississippi. It is one of the largest bears in the fossil record and was among the largest mammalian land predators of all time. The type specimen came from Potter Creek Cave in Shasta County, California. In a recent study, the mass of six A. simus specimens was estimated, one-third of them weighed about 900 kg (1 short ton), the largest being UVP 015 at 957 kg (2,110 lb), suggesting specimens that big were probably more common than previously thought. evidently this was about average: 900 kilograms is equal to 1,984.16 pounds (avoirdupois)... ( 1 ton ).
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Post by King Kodiak on Feb 20, 2019 12:40:07 GMT -5
900 kg (1985 lbs), and that is basically the only average weight info we have. One third out of 6 specimens weighted. That is a huge bear.
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Post by King Kodiak on Feb 20, 2019 17:45:30 GMT -5
A TERRITORIAL DISPUTE BETWEEN 2 ARCTODUS SIMUS.
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Post by brobear on Feb 20, 2019 18:20:12 GMT -5
dc.etsu.edu/etd/1477/ The paleobiology of the Pleistocene North American giant short-faced bear, Arctodus simus, has eluded paleontologists for decades. Its more gracile form has led past researchers to myriad intepretations of the locomotion and feeding ecology of this species. While earlier studies have focused on craniodental morphology and simple postcranial indices, it is forelimb morphology that represents a direct compromise between locomotor and foraging behavior. The study here uses traditional and 3D landmark morphometrics to more completely compare the 3-dimensional shape of the major forelimb elements and their muscle attachment sites between A. simus, extant ursids, and other carnivorans. Results herein agree well with previous studies and provide additional evidence for reduced abductor/adductor and supinator/pronator musculature, more restricted parasagittal motion, increased stride length, and lighter and more packed distal elements. Forelimb skeletal morphology therefore supports the hypothesis that A. simus represents a bear in the early stages of cursorial evolution. Again - Forelimb skeletal morphology therefore supports the hypothesis that A. simus represents a bear in the early stages of cursorial evolution.
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Post by King Kodiak on Feb 22, 2019 5:50:45 GMT -5
Arctodus Simus here either killing or finding an animal.
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Post by brobear on Feb 28, 2019 1:11:55 GMT -5
From - wildfact.com/forum/The Giant Short Faced Bear was 1,5 to 1,80 m (5 to 6 feet) tall at the shoulder and rose to an impresive 3 m (10 feet) when standing on its hind legs, it weighted 600 to 800 kgs (1320 - 1760 pounds) the giant was taller than a Polar Bear . The short muzzle gave it a more lion-like face than other bears, it has a relatively wide skull and very powerful jaws. Its closest living relative is the South American Spectacled Bears. What did they eat? Analysis of the bones of Short Faced Bears shows that they were exclusive meat eaters and they were well adapted to this task, their shortened jaws would have brought their crushing teeth closer to the back of the skulland so have increased their power. This Bear seen to be adapted for cracking large bones to extract the nutritious marrow. Book Prehistoric America - Miles Barton, Nigel Bean, Stephen Dunleavy, Ian Gray, Adam White.
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Post by King Kodiak on Feb 28, 2019 17:35:27 GMT -5
This site has not been posted yet in this thread, is from the Alaska department of fish and game.
“Arctodus weighed about 1,600 pounds to 1,900 pounds,” says Matheus.”
You are watching a pride of lions gorging on the still-warm carcass of a young elephant. Wild horses graze nearby, wide ears active, great marble eyes rolling nervously toward the preoccupied cats. Suddenly the lead stallion raises his head and snorts in alarm. His harem of mares dance in sudden agitation, staring off in the distance. Slowly climbing over the horizon, a looming form approaches at a steady pace. As one, with the synchrony of a wheeling flock of birds, the herd bolts. The lions grumble deep in their throats and rise to stand at point.
The animal is closer now. Close enough for you to realize that it is the largest bear you have ever seen. You crouch frozen, adrenaline coursing through you like a rushing river. You are transfixed by the size of this beast. As the bear passes, its odor fills your nostrils, the rotten-flesh stench of a carnivore.
The lions, heads low, a steady growl of warning rumbling from within, turn to block the carcass, to face off against their nemesis…
Just another tale of survival in the Alaska wilderness. But wait. Lions, wild horses, and elephants in Alaska? You bet. During the Pleistocene epoch (from 1.8 million to 10,000 years ago) all of these creatures roamed the grassy steppes that would later become the boreal forests of Interior Alaska. In fact, the confrontation between the pride of steppe lions and the short-faced bear (Arctodus simus) over that mammoth carcass could have easily taken place where the University of Alaska Fairbanks campus sits today.
This is strangely appropriate, since several mysteries surrounding this bear were solved within a bone-filled, dusty lab of UAF less than a decade ago. Paul Matheus, then Director of the Alaska Quaternary Center, challenged some long accepted beliefs about the life history of this mega bear. Thanks to his research, we now may know what Arctodus ate, how it procured its food and even the most plausible explanation for its sudden disappearance a scant 12,000 years ago.
The short-faced bear first loped into paleontological prominence in 1967, when Dr. Bjorn Kurten of the University of Helsinki authored a paper entitled, Pleistocene Bears of North America. Kurten wrote that Arctodus was “…by far the most powerful predator in the Pleistocene fauna of North America.”
Though Dr. Matheus is quick to express his deep respect for Kurten’s work, to the point of reverently referring to the world renowned Finnish paleontologist as the “bear god,” he does not agree with Kurten’s conclusion that the bear was a formidable predator.
Quarternary biologists, who study the life forms of the Pleistocene, encounter a range of obstacles when trying to determine what ecological niche an extinct animal may have occupied. They can’t climb a hill and make observations through a spotting scope. They have to rely on evidence left behind, mainly bones.
The bones that individual short-faced bears left behind tell us that this bear ate meat. The skull has a shortened snout and powerfully built jaws that could crush bone. Matheus says that Arctodus’ canine teeth were well suited for puncturing tough hide, and its large, jagged molars were ideal for gnawing, tearing, and slicing meat.
These physical attributes, alone, however, are not sufficient to prove that the short-faced bear was a true carnivore and not an omnivore, as are today’s modern grizzlies and black bears. Matheus used a technique called “stable isotope analysis” to quell any doubts about Arctodus’ diet. Simply put, nitrogen occurs in nature in two forms, nitrogen-15 (15N) and nitrogen-14 (14N). The ratio of 15N to 14N in a bone sample can tell researchers whether an animal was a carnivore, an herbivore, or an omnivore. Matheus found a very high 15N to 14N ratio in all the Arctodus bone samples he tested. This nitrogen “signature” is indicative of a true carnivore. Thus, the stable isotope analysis when coupled with the physical characteristics of fossil skulls and teeth leaves little room for argument: The short-faced bear ate only meat.
“Arctodus weighed about 1,600 pounds to 1,900 pounds,” says Matheus. That’s roughly twice the weight of the average modern Alaska coastal brown bear. “On hind legs, it stood 8 feet to 10 feet tall.” Even on all fours, Arctodus could look a 6-foot man in the eye. It’s tempting to assume that, since this bear was such an outsized carnivore, it was the alpha predator of its time. It isn’t difficult to imagine Arctodus pulling down woolly mammoths or steppe bison, or crushing the spine of a Pleistocene moose with one swipe of a sledgehammer paw. But, the ancient bones that Matheus studied, whispered a different story.
“There are two lines of thinking about Arctodus as a predator,” Matheus explains. “The first I call ‘The Linebacker Hypothesis.’ It envisions a mighty brute that overwhelmed the largest mammals of the Pleistocene. The bear supposedly used its massive body to tackle things like mammoths and giant ground sloths. The problem with this idea is that Arctodus, though very large, was very gracile (light-boned). In order to bring down these magafauna (large animals), Arctodus would have to have been a more robust creature sporting thicker, stronger bones.”
Matheus calls the second theory, “The Cheetah Hypothesis.” Some believe the long-legged Arctodus was able to run down smaller, fleet-footed Pleistocene herbivores such as steppe horses and saiga antelopes. In this scenario however, the short-faced bear’s sheer physical mass would be a handicap. “Size works against you in developing speed,” notes Matheus. “Once an animal tops 320 pounds to 400 pounds, additional weight sacrifices speed. Furthermore, Arctodus’ skeletal structure does not articulate in a way that would have allowed it to make quick turns, an ability required of any predator that survives by killing agile prey.”
After studying the skeletal record, Matheus determined that Arctodus was a pacer. That is, both of its right legs moved forward together, then both left legs moved forward in unison. This is the primary means of locomotion for elephants and camels. Pacing isn’t particularly fast, but it is very energy-efficient. An animal that is built for pacing is designed for endurance rather than speed.
So where does this leave Arctodus in the grand Pleistocene scheme? This monster ate only meat, yet it seems to have been ill equipped physically as a hunter. Matheus believes the answer is clear, and reflects some recent theories concerning another prehistoric monster, Tyrannosaurus: “Arcotdus,” he claims, was a scavenger.” The largest bear to have ever paced the earth depended upon other predators to make the kills it needed to survive.
“Arctodus located carrion by rising up on its hind feet and sniffing the air,” Matheus surmises. “Standing is something to which its skeleton was well suited.” The tall bear’s upright posture would have placed its wide nose high in the air, allowing it to detect even far off food sources. Arctodus could then drop down on its lanky legs and pace steadily, tirelessly, to even distant kills. Once there, the bear probably used its size to intimidate lesser carnivores and drive them away from their prey.
The short–faced bear was, in this way well-suited for survival in Pleistocene Alaska, but its fate may have been inextricably linked to the climate of that age. The warming temperatures that caused the great glaciers sheeting much of the North American continent at the time to recede also gradually transformed the arid, grassy steppes of Interior Alaska into the boreal forests of today.
The steppe horse, woolly mammoth and saiga antelope, as well as the predators that brought them down were grassland creatures and thus slowly disappeared as the forest took over their grassland habitat. The great bear could not scavenge enough food to support its mighty bulk. Unlike its cousins, the cave bear, grizzly, and black bear, Arctodus could not supplement its diet with fruits and vegetation. In the end, Alaska’s mightiest carnivore was essentially done in by trees. The same trees that so altered the grassland habitat that prey animals and their predators went extinct, left nothing for the great bear to scavenge.
The bear stands on its hind legs, emphasizing its size. It is the tallest thing on the steppe. Your knees quiver, you try to quiet your breath, your heart. The lions crouch, tail-tips wriggling. Suddenly the monster slams its weight down on lanky front legs and charges the waiting defenders. The dominant lion dodges and tries a lunge from the side, but the bear swings one massive paw and the cat is gone, tumbling and bouncing like a rock chucked across the grass. The remaining felines snarl, lips drawing black lines above razor teeth, haunches trembling in indecision. Injured, the downed cat struggles to its feet, hobbles off dragging a hind leg, and the rest of the pride breaks from the kill to follow. Arctodus moves in on the mammoth carcass. As you slink away, stepping carefully, the sound of cracking bones hurries you across the steppe.
You head for home, too shaken to resume hunting now. There will be time to try again tomorrow, for this new land you entered a season ago abounds with game. The grasses are green and lush. And between the waving blades, a new growth is emerging. Its woody stems support spade-like leaves that quake hypnotically in the breeze. You pause to wonder at them, then lay down your spear and allow the heavy bison hide to slide off your shoulders. After all, it is an unusually warm day.
For more information about the short-faced bear and other amazing Pleistocene animals, visit www.beringia.com.
Nancy Sisinyak is an information officer with the the Alaska Department of Fish and Game, Division of Sport Fish, and lives in Fairbanks.
www.adfg.alaska.gov/index.cfm?adfg=wildlifenews.view_article&articles_id=232
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Post by brobear on Mar 1, 2019 11:42:16 GMT -5
Nice find King Kodiak. An astonishing look at the Lord of Pleistocene N. America.
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Post by King Kodiak on Mar 1, 2019 16:46:11 GMT -5
Nice find King Kodiak. An astonishing look at the Lord of Pleistocene N. America. Thanks brobear. By the way, very interesting, from the above post, looks like a recreation of Simus displacing a lion pride. The lions crouch, tail-tips wriggling. Suddenly the monster slams its weight down on lanky front legs and charges the waiting defenders. The dominant lion dodges and tries a lunge from the side, but the bear swings one massive paw and the cat is gone, tumbling and bouncing like a rock chucked across the grass. The remaining felines snarl, lips drawing black lines above razor teeth, haunches trembling in indecision. Injured, the downed cat struggles to its feet, hobbles off dragging a hind leg, and the rest of the pride breaks from the kill to follow
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Post by brobear on Mar 3, 2019 2:41:49 GMT -5
Skeleton mounted bipedally and it stands just under 10 feet tall, and right about 8 feet at the shoulders. Information of skeleton and picture courtesy of Mr William Simpson Head Collection of Field Museum in Chicago, USA First posted by epaiva.
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Post by Deleted on Mar 6, 2019 10:20:03 GMT -5
How many American lions are needed to kill a giant short faced bear?
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Post by King Kodiak on Mar 6, 2019 22:37:27 GMT -5
How many American lions are needed to kill a giant short faced bear? I would say 2 at once would be enough, but they will get injured.
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Post by brobear on Mar 7, 2019 2:10:25 GMT -5
shaggygod.proboards.com/ Despite these uncertainties we hypothesize that A. simus would have been more carnivorous than other southeastern bears and therefore filled a different ecological niche than did T. floridanus and U. americanus. Its primary competitors in the large carnivore guild of the southeast would have been dire wolf (Canis dirus Leidy, 1858) and large felids like Panthera atrox (Leidy, 1853), Panthera onca (Linnaeus, 1758) and Smilodon fatalis (Leidy, 1868). The much larger body size of A. simus would have provided an advantage in disputes over carcasses. The paleodiet and ecological relationships of late Pleistocene bears could be further analyzed with isotopic and microwear analyses. BW Schubert, RC Hulbert Jr. 2010. Paleontological Soc, Giant short-faced bears (Arctodus simus) in Pleistocene Florida USA, a substantial range extension. Journal of Paleontology; 84: 79-87.
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Post by King Kodiak on Mar 7, 2019 8:01:34 GMT -5
“The much larger body size of A. simus would have provided an advantage in disputes over carcasses.”
no Pleistocene big cat in his right mind would have defended a kill from the master. Better to go out hunting another day than to die today.
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Post by brobear on Mar 27, 2019 8:02:41 GMT -5
“The much larger body size of A. simus would have provided an advantage in disputes over carcasses.” no Pleistocene big cat in his right mind would have defended a kill from the master. Better to go out hunting another day than to die today.
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Post by King Kodiak on Mar 27, 2019 9:11:33 GMT -5
Beautiful representation there brobear. Simus looks pissed off, lmao. 2 big cats being displaced off their kill....not surprising.
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Post by BruteStrength on Mar 27, 2019 17:06:30 GMT -5
Shortface bear is too much for most big cats. This bear was simply too big for cats to tackle.
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Post by Deleted on Mar 27, 2019 22:10:43 GMT -5
The short faced bear is actually the most slim of all bears pound to pound and still it manages to chase away two smilodons which seems to indicate this bear is acustomed to fighting off multiple opponents. If this short faced bear weighs a tonne or even 900 kgs in the picture below (credited to brobear): The I am confident an exceptional 800 to 1000kg polar bear can fight off more than two smilodons or american lions and four african lions (the smilodons or american lions and african lions will only work with their own kind of course ) since a polar bear is more heavily built than a giant short faced bear pound to pound.
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Post by King Kodiak on Mar 28, 2019 3:18:35 GMT -5
The I am confident an exceptional 800 to 1000kg polar bear can fight off more than two smilodons or american lions and four african lions (the smilodons or american lions and african lions will only work with their own kind of course ) since a polar bear is more heavily built than a giant short faced bear pound to pound. Yeah i agree, that should be able to happen. An exceptional 700-800 lb polar bear should. There are no 1000 kg specimens. That was only 1, the largest modern polar bear.
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Post by BruteStrength on Mar 28, 2019 14:26:51 GMT -5
I think the only bear that can fight off more than 2 big cats is the almighty shortface bear. Some shortface bears were able to reach weights of over 3,000 pounds.
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