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Post by brobear on Apr 1, 2017 19:35:05 GMT -5
Arctotherium
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Post by brobear on Apr 1, 2017 19:55:42 GMT -5
www.biolib.cz/en/taxonposition/id608915/ system Vitae - living organisms domain Eukaryota Whittaker & Margulis, 1978 - lifeforms with nucletic cells superregnum Unikonta system Opisthokonta Cavalier-Smith, 1987 kingdom Animalia Linnaeus, 1758 - animals subregnum Eumetazoa Butschli, 1910 divisio Bilateria Hatschek, 1888 - Bilaterians subdivisio Deuterostomia - deuterostomes phylum Chordata Bateson, 1885 - chordates subphylum Vertebrata Cuvier, 1812 - vertebrates infraphylum Gnathostomata Zittel, 1879 - jawed vertebrates superclassis Tetrapoda Gaffney, 1979 - four-limbed vertebrates class Mammalia Linnaeus, 1758 - mammals subclass Theria Parker & Haswell, 1897 infraclass Eutheria Thomas Henry Huxley, 1880 order Carnivora Bowdich, 1821 - carnivores suborder Caniformia Kretzoi, 1938 - dog-like superfamily Ursoidea Fischer de Waldheim, 1817 family Ursidae Fischer von Waldheim, 1817 - bears subfamily Tremarctinae Merriam & Stock, 1925 genus Arctotherium Bravard, 1857 † species Arctotherium bonariense (Gervais, 1852) - Buenos Aires Bear †
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Post by brobear on Apr 5, 2017 12:39:48 GMT -5
There were five species of Arctotherium. 1 - Arctotherium angustidens. 2 - Arctotherium vetustum. 3 - Arctotherium wingei. 4 - Arctotherium bonariense. 5 - Arctotherium tarijense.
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Post by brobear on Apr 30, 2017 4:14:42 GMT -5
First posted by Epaiva: Arctotherium wingei it was a small Bear that weighted up to 300 kilograms and measured 2 meters long. 300 kg = 660 pounds. 2 meters = 6 feet 7 inches.
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Post by brobear on May 8, 2017 12:12:45 GMT -5
cameronmccormick.blogspot.com/2011/01/arctotherium-angustidens-biggest-bear.html Sunday, January 23, 2011 Arctotherium angustidens: Biggest Bear Ever? I have a bit of an obsession with animal size superlatives, and megabears* are among my favorites - that's right, I have interests beyond testudines. Anyways, in this blog's even more poorly-written past, I discussed purported giant hypercarnivores wherein I argued that the One-Ton(ne)-Hyperpredatory-Arctodus meme is unsubstantiated Godzillafication which somehow managed to infect even some peer-reviewed literature. Brian Switek wrote an article at the old Laelaps covering newer research which further demolished the mythology of the Giant Short-Faced Bear: it didn't have a short face (it did have a deep snout), or particularly long legs (somewhat of an optical illusion caused by a short back), and was probably a generalist omnivore like extant bears (presumably with some differences in niche, of course). Just as it seemed that speculations about One-Ton(ne)-Hyperpredatory-Bears would be a thing of the past, this happened: Arctotherium is composed of 5 South American species - of which A. angustidens is the earliest, largest, and apparently most predatory - and is the sister clade of Arctodus; the two are in turn part of the clade Tremarctinae which further includes Tremarctos (spectacled bear and kin) and Plionarctos (Soibelzon and Schubert 2011). The Arctotherium angustidens specimen of concern is not a new discovery, as it was found prior to 1935 during construction of a hospital in La Plata, Argentina (Soibelzon and Schubert 2011). It is presently composed of radii, ulnae, and humeri from both forelimbs; metacarpals, phalanges, and a scapula fragment were also recovered but unfortunately lost (Soibelzon and Schubert 2011). The dimensions of the bones* are incredible, the humerus has a length of 62 cm (2' 0.4") and the mid-shaft humerus width is 9 cm (3.5"); comparable maximum measurements of other giants bears are: Arctodus simus - 59.4 cm/6.4 cm; Ursus spelaeus - 44.8 cm/5.6 cm; and Ursus maritimus - 38.5 cm/4.65 cm (Soibelzon and Schubert 2011). For those who would prefer a more graphical comparison: Using humerus greatest length, humerus mid shaft circumference, humerus greatest distance of distal epiphysis, and radius proximal epiphysis greatest diameter, the estimated weight for the giant Arctotherium angustidens specimen ranged from 983-2042 kg (2,167-4,502 lbs), with the value likely around the mean and median of 1588 and 1749 kg (3501-3856 lbs), respectively (Soibelzon and Schubert 2011). The other known specimens were given the same treatment (when possible), and a couple of them appeared to mass around a tonne (Soibelzon and Schubert 2011). This would seem to suggest that the giant Arctotherium angustidens specimen was not an outsized freak, and could represent a "normal" maximum size for the species. Before too many conclusions can be made, some more discussion of the specimen is in order. The most striking aspect of this specimen are the osteogenic changes to the deltoid crests of both humeri - more apparent in the left humerus pictured above, see arrow - and the distal third of the left radius shaft, which suggest a deep injury followed by infection and then new vascular growth over a long period of time (Soibelzon and Schubert 2011). Judging by the high degree of epiphyseal fusion, the specimen managed to become an old adult (Soibelzon and Schubert 2011). Humeral mid-shaft measurements gave on average larger estimated masses (Soibelzon and Schubert 2011 - Table 3), which makes me wonder if the measurements were artificially inflated by the injury and subsequent pathological growth. However, the limited data on Table 3 shows similar proportions with a somewhat smaller specimen: Curiously, specimens of Arctotherium angustidens appear to differ considerably in limb proportions, for instance, two specimens have the same humeral circumference (22 cm) but the greatest diameter of the distal humeral epiphysis differs considerably (20.5 vs. 18 cm), one of which is larger than the giant specimen's maximum measurements (18.5 cm) (Soibelzon and Schubert 2011)... this is certainly confusing, and the value of compiling median and mean figures is readily apparent. While the mass of the giant Arctotherium angustidens cannot be precisely pinned down, the available evidence suggests it exceeded all other bears in size. ... or does it? Incredibly, one mass regression of Indarctos atticus exceeded 3 metric tonnes, although predictably it was found to be highly improbable (Finarelli and Flynn 2006) and, along with fellow Mio-Pliocene bear Agriotherium, they are not believed to have reached the same size as Arctodus simus or Arctotherium angustidens (Soibelzon and Schubert 2011). Polar bears (U. maritimus) can get extremely large*, with one specimen shot in Alaska in 1960 purportedly standing 3.39 m (11' 1.5") and weighing 1002 kg (2210 lbs); the whereabouts are apparently unknown and the skull was never submitted for measurement (Wood 1981). Assuming the record is genuine, I'm wondering if the height included unnaturally straitened legs or was in fact the length lying down and outstretched, which would certainly be easier to take. Considering the largest Arctotherium angustidens humeral length is about 160% as large as the largest polar bear measurement included in Soibelzon and Schubert (2011), it would take one freakish polar bear to get that tall, and it would probably weigh a lot more than a tonne. Polar bears reached their largest sizes in the late Pleistocene (Soibelzon and Schubert 2011) and Ursus maritimus "tyrannus" apparently had an ulna 44 cm in length (see Markus Bühler's Bestiarium, comment #5), which is of course smaller than that of the specimen in question's (57 cm), but still surprisingly large for a single specimen. Information on these giant polar bears is unfortunately quite hard to come by, but I think it's safe to assume it didn't exceed Arctotherium angustidens in size, at least regularly. Exactly how the average sizes of the giant bears compare is difficult to determine at the present time - particularly when gender isn't obvious. However, as weights of a tonne or more appear to have been reached by Arctotherium angustidens regularly, the average must have considerably exceeded that of other giant bears, which have only been demonstrated to exceed a tonne in one instance. The authors' assertion that Arctotherium angustidens was the biggest bear ever is well-supported, until something bigger turns up.
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Post by brobear on Jan 31, 2018 5:12:46 GMT -5
Compared to ancient bears, modern bears are relatively tame. Then again, today’s bruins don’t have to carve out territory from other terrifying predators such as saber-toothed cats, packs of dire wolves, cave lions, and even massive carnivorous, cow-sized pigs that were more likely to charge you—and eat you—then run away. Ancient bears did all that and what’s more, they were usually the strongest of the strong. Other predators might be quicker or even smarter, but beyond the dinosaurs, few land predators could boast to be as powerful as a bear. Here is our list of five ancient, extinct bear species that would give modern bears a run of their money. Much like our list of massive ancient deer however, it goes to show that after the ice age, size actually ended up being a disadvantage. The bears on this list either evolved into a smaller version, or simply died out altogether. Could you imagine taking on one of these beasts during bear season? That .450 Marlin may no longer cut it. 1. History’s largest bear (Arctotherium angustidens) This is quite simply, the largest bear ever discovered and by default, a contender for the largest carnivorous land mammal ever to live. The Arctotherium angustidens was isolated primarily to South America during the Pleistocene epoch 2.5 million to 11,000 years ago. This bear was so massive that scientists believe it regularly weighed between 2,000 and 4,000 pounds, although newer estimates have brought down the upper end of that scale to around 3,500 pounds. Still, that meant that these huge ancient bears outweighed their largest modern equivalents—Kodiak and polar bears—by a significant margin. The Arctotherium’s closest living relative, spectacled bears, only weighs less than a ninth of these behemoths. When standing on its hind legs, the angustidens measured about as tall as the largest modern bears, but its true power lay in the robust construction of its body. Heavily muscled and far stouter than today’s bears, the angustidens was a predator unlike any other. It often challenged the other apex predators of its day, such as saber-toothed cats, and won. As for its diet, it routinely ate other megafauna such as giant armadillos, ancient toxodons, and even camels. Unfortunately, its large bulk was also its main liability. The angustidens sound found itself outnumbered and outclassed by smaller, swifter predators such as the jaguar. These more mobile predators soon dominated predatory niches once occupied by the bear, and the species adapted by becoming smaller and quicker itself. It survives into the modern day as the spectacled bear, which remains the largest predator in South America, but only a pale shadow of the powerful carnivore it once was. www.outdoorhub.com/stories/2015/11/02/five-prehistoric-bear-species-mop-floor-modern-bears/
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Post by brobear on Oct 3, 2018 6:58:37 GMT -5
Post by brobear on less than a minute ago www.wired.com/2011/02/demythologizing-arctotherium-the-biggest-bear-ever/ Depending on the estimation method used, the Arctotherium from La Plata City weighed anywhere between 2,162 and 4,500 pounds, although the authors admit that the upper limit is a bit too high. Instead, they propose that male Arctotherium angustidens maxed out around 3,500 pounds, and a skeletal reconstruction included in the paper is just shy of eleven feet tall. This is about as tall as the largest grizzly and polar bears can stand, but Arctotherium angustidens was a much more robust animal. *3,500 pounds ( 1600 kg ) is still a gigantic bear ( MAX SIZE ).... probably averaged a full ton.
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Post by King Kodiak on Oct 3, 2018 7:23:09 GMT -5
Yeah a 3.500 lb bear, my god. Be scared, very scared.
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Post by brobear on Oct 3, 2018 11:59:41 GMT -5
Quote from above post: a skeletal reconstruction included in the paper is just shy of eleven feet tall. This is about as tall as the largest grizzly and polar bears can stand. *I don't think so. The record 2200 pound polar bear was mounted at 11 feet tall. True. But it was mounted in a very unnatural pose which would be impossible for a live bear. Perhaps this "biggest modern polar bear ever" stood just over 10 feet tall, but that is the best we have. Some Kodiak bears have been estimated at 12 feet tall. This I will only accept when actually measured.
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Post by brobear on Oct 12, 2018 10:12:11 GMT -5
www.bioone.org/doi/abs/10.1666/13-143?journalCode=pleo South American giant short-faced bear (Arctotherium angustidens) diet: evidence from pathology, morphology, stable isotopes, and biomechanics. Accepted: June 11, 2014 Abstract Arctotherium angustidens Gervais and Ameghino, 1880 (the South American giant short-faced bear) is known for being the earliest (Ensenadan Age, early to middle Pleistocene) and largest (body mass over 1 ton) of five described Arctotherium species endemic to South America. Here we assess the diet of this bear from multiple proxies: morphology, biomechanics, dental pathology, stable isotopes and a previous study using geometric morphometric methodology. Results favor the idea of animal matter consumption, probably from large vertebrates in addition to vegetable matter consumption. Most probably, active hunting was not the unique strategy of this bear for feeding, since its large size and great power may have allowed him to fight for the prey hunted by other Pleistocene carnivores. However, scavenging over mega mammal carcasses was probably another frequent way of feeding. South American short-faced bears adjusted their size and modified their diet through Pleistocene times, probably as a response to the diversification of the carnivore guild (from the few precursory taxa that crossed the Panamanian Isthmus during the Great American Biotic Interchange).
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Post by brobear on Oct 12, 2018 10:16:24 GMT -5
dinopedia.wikia.com/wiki/Arctotherium in: Omnivores, Pliocene Mammals, Pleistocene Mammals, and 3 more Arctotherium Name Arctotherium angustidens Order Carnivora Family Ursidae Class Mammalia Name Translation Bear Beast Period Late Pliocene-Pleistocene epochs of the Cenozoic Era Location South America Diet Omnivore Length 4.5 meter Arctotherium is an extinct genus of South American short-faced bears within Ursidae of the late Pliocene through the end of the Pleistocene. Their ancestors migrated from North America to South America during the Great American Interchange, following the formation of the Isthmus of Panama. They were endemic to South America, living from ~2.0–0.01 Million years ago, existing for approximately 1.99 million years. Their closest relatives were the North American short-faced bears of genus Arctodus (A. pristinus and A. simus). The closest living relative would be the spectacled bear (Tremarctos ornatus). Arctotherium was named by Hermann Burmeister in 1879. It was assigned to Tremarctinae by Krause et al. 2008. A humerus of A. angustidens from Buenos Aires indicates that the big males of this species would have weighed 2.2 tonnes, standing 14 feet tall, making it the largest bear and largest carnivorous land mammal known. In contrast to their North American cousins, South American short-faced bears showed a trend of declining size and carnivory over time. This has been attributed to increased competition from other, later-arriving or evolving carnivorans, like jaguars or lions, following the early dispersal of short-faced bears to South America. (The North American carnivorans that invaded South America, including short-faced bears and Smilodon, quickly dominated the predatory niches formerly occupied by South America's native metatherian sparassodont and avian phorusrhacid carnivores.) Description Actotherium was the largest bear, known at this time. Compared with Arctodus simus, it had a more powerful physique with the same linear dimensions and was also very much robustly build. Representatives of this species reached 4.7 m in length and weighed about 2,200 kg. . The calculations were made on the basis of seven different measurements of animal bones. Arctotherium angustidens lived during the Pleistocene, the Argentine plains. At one time (2 million - 500 thousand years ago) it was the largest predator on the planet. It appeared to have been omnivorous, but large herbivores were the basis of its diet. Some competition it could make is with the sabre-toothed cats, who were also at the top of the food chain. The closest relative of A. angustidens is that of the living spectacled bear, which is significantly lost in size compared to its distant ancestor
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Post by brobear on Oct 22, 2018 11:18:21 GMT -5
shaggygod.proboards.com/ The Largest Known Bear, Arctotherium angustidens, from the Early Pleistocene Pampean Region of Argentina: With a Discussion of Size and Diet Trends in Bears Abstract The South American giant short-faced bear (Arctotherium angustidens Gervais and Ameghino, 1880) is one of five described Arctotherium species endemic to South America and it is known for being the earliest, largest, and most carnivorous member of the genus. Here we report an extraordinarily large A. angustidens individual exhumed from Ensenadan sediments (early to middle Pleistocene) at Buenos Aires Province, Argentina. Based on overall size, degree of epiphyseal fusion, and pathologies, this bear was an old-aged male that sustained serious injuries during life. Body mass of the bear is estimated and compared to other ursid species based on a series of allometric equations. To our knowledge, this specimen now represents the largest bear ever recorded. In light of this discovery, we discuss the evolution of body size in Arctotherium (from large-to-small) and compare this to bears that exhibited different evolutionary trajectories. We suggest that the larger size and more carnivorous nature of A. angustidens, compared to later members of the genus, may reflect the relative lack of other large carnivores and abundance of herbivores in South America just after the Great American Biotic Interchange.
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Post by brobear on Dec 9, 2018 5:14:56 GMT -5
www.ancientpages.com/2018/03/15/skull-and-jaw-of-giant-bear-of-the-late-pleistocene-found-in-buenos-aires/ Skull And Jaw Of Giant Bear Of The Late Pleistocene Found In Buenos Aires. AncientPages.com - Researchers in Argentina report they have discovered remains of a giant bear of the late Pleistocene, near Buenos Aires. It’s an extraordinary find and the skull and jaw of this giant bear are still almost complete. The discovery was made on the banks of the Salado River, northwest of the province of Buenos Aires, a paleontological site has revealed a lot of fossils in recent weeks. In an interview with CTYS-UNLaM Agency, paleontologist of the Museo La Plata and CONICET Leopoldo Soibelzon explained that find a bear in the Pampean region is an extraordinary find. "Finding a carnivore already is an extraordinary finding because they are always fewer in ecosystems," said Dr. Soibelzon. He added: "And within carnivores, the bears are not frequently found, and even less a complete skull with a jaw, as was found now in Junin." According to experts, “it is an excellent material, because the most frequent thing is to find a tooth, a canine, a phalanx, a piece of a long bone, but finding a complete skull with jaw is very interesting.” The giant bear belongs to the genus of the Arctotherium, among which is the largest specimen of the record. "This material from Junín surely corresponds to the late Pleistocene, with an age that does not exceed 120 thousand years, while giant bears of greater size existed in South America during the early Pleistocene, almost a million years ago." The largest specimen known, belonging to the species Arctotherium angustidens, was a carnivore-omnivore that lived 780 thousand years ago and was discovered in the city of La Plata. "Since the middle of the Pleistocene, the bears were decreasing in size and, within their omnivorous diet, they were becoming a little more herbivores, but in comparison to the size of the current bears, this copy of Junín was also gigantic," said Dr. Soibelzon. “This practically complete skull is missing what would be the right cheekbone, the zygomatic arch and part of the maxilla; then, it has even the two mandibular branches, although it also lacks the piece that joins both mandibles,” Professor José María Marchetto, director of the Museo del Legado del Salado de Junín said. For his part, Dr. Luciano Brambilla, a biologist at the National University of Rosario, agreed that "it is extraordinary to find a fossil bear, but strikingly, in Junín, another specimen had been found decades ago; it's as if two needles had been found in a haystack. " According to CTYS-UNLaM Agency, “last Friday, fragments of a phalanx and a metapodium were found - bones that are part of what would be the hand or leg of a saber-toothed tiger. The bear and saber-toothed tiger are presented as the most striking findings in the midst of a large number of fossils of herbivorous animals that continue to emerge in this site located northwest of Buenos Aires. There are remains of species that inhabited the Pampean region towards the end of the Pleistocene, until its extinction about 10 thousand years ago.” Scientists are now working to ensure this site is declared a reserve. It is vital not only to protect the paleontological site, but also the flora and fauna of the place.
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Post by King Kodiak on Dec 10, 2018 17:35:25 GMT -5
Standing at 11 Feet: World's Largest Known Bear Unearthed By Charles Q. Choi, Live Science Contributor | February 1, 2011 10:42am ET 0 0 MORE Standing at 11 Feet: World's Largest Known Bear Unearthed The largest land predator of its time, the South American giant short-faced bear (Arctotherium angustidens), in comparison to a person. Credit: Soibelzon, Schubert, Journal of Paleontology. The fossils of the largest known bear to have ever lived have been found, a giant that was the most powerful land carnivore of its time, scientists said. ADVERTISING inRead invented by Teads The remains were unearthed during the construction of a hospital in La Plata City, Argentina. It was a South American giant short-faced bear (Arctotherium angustidens), the earliest and largest member of its genus (its group of species of bears). This titan lived between 2 million to 500,000 years ago, with its closest living relative being the spectacled bear (Tremarctos ornatus) of South America. Advertisement ADVERTISEMENTSCROLL TO CONTINUE WITH CONTENT Based on measurements of the fossil's leg bones and equations used to estimate body mass, the researchers say the bear would have stood at least 11 feet tall (3.3 meters) on its hind legs and would have weighed between 3,500 and 3,855 pounds (1,588 and 1,749 kilograms). In comparison, "the largest record for a living bear is a male polar bear that obtained the weight of about 2,200 pounds (1,000 kg)," said researcher Leopoldo Soibelzon, a paleontologist at the La Plata Museum. Climate Change is Making Sharks Right-Handed "During its time, this bear was the largest and most powerful land predator in the world," researcher Blaine Schubert, a paleontologist at East Tennessee State University in Johnson City, told LiveScience. "It's always extremely exciting to find something that's the largest of its class — and not just a little bit larger, but quite a bit larger." Although this bear probably had an omnivorous diet, flesh likely dominated. Megafauna or large creatures likely played an important role in what it ate, and potentially included giant ground sloths, now-extinct relatives of elephants, camels, tapirs, and armadillo-like creatures known as glyptodonts. Advertisement "This does not imply that active hunting was its primary strategy for feeding, since its large size and great power may have permitted the bear to fight for prey hunted by other Pleistocene carnivores such as the saber-toothed cat," Schubert said. "Scavenging megaherbivore carcasses was probably another frequent way of feeding." The research team's analysis of the bear's bones suggests it was an old male that survived a number of serious injuries during life. These might have come from battles with other males, while hunting megafauna, or during fights with other carnivores over a carcass. The scientists also suggested the reason why this species might have grown so huge. When bears arrived in South America after the land bridge between the Americas appeared about 2.6 million years ago, there were relatively few other large predators there at the time, with the exception of the saber-toothed cat. The bears then grew, taking advantage of the large amount of prey, researchers suggested. The species eventually became extinct after more carnivores evolved in South America. Soibelzon and Schubert detailed their findings in the January issue of the Journal of Paleontology. www.livescience.com/11701-standing-11-feet-world-largest-bear-unearthed.html
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Post by brobear on Dec 11, 2018 6:24:38 GMT -5
Quote from above post: The research team's analysis of the bear's bones suggests it was an old male that survived a number of serious injuries during life. These might have come from battles with other males, while hunting megafauna, or during fights with other carnivores over a carcass. Evidently, like the grizzly, Arctotherium fought often too. Fights can occur from displacing other predators, fighting with other bears over food or over a she-bear. Also possible that Arctotherium was territorial, but unlikely we will ever know.
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Post by BruteStrength on Dec 11, 2018 12:43:05 GMT -5
The south american short face bear was definitely a freak of nature. The skeleton of one is truly scary.
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Post by brobear on Dec 23, 2018 12:40:13 GMT -5
Arctotherium angustidens - carnivora.net/index.phpArctotherium is an extinct genus of South American short-faced bears within Ursidae of the late Pliocene through the end of the Pleistocene. They were endemic to South America living from ~2.0–0.01 Ma, existing for approximately 1.99 million years. Their closest relatives were the North American short-faced bears of genus Arctodus (A. pristinus and A. simus). The closest living relative would be the Spectacled bear (Tremarctos ornatus). A specimen of A. angustidens from Buenos Aires shows an individual estimated, using the humerus, to weight between 983–2,042 kg (2,170–4,500 lb), though the authors consider the upper limit as improbable and say that 1,588 kg (3,500 lb) is more likely, however, using the radious, the mass estimate shrinks to a maximum of 1,108 kg (2,440 lb).
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Post by brobear on Jan 10, 2019 4:29:49 GMT -5
Paractotherium pamparum www.academia.edu/1487943/The_southernmost_bear_Pararctotherium_Carnivora_Ursidae_Tremarctinae_in_the_latest_Pleistocene_of_Southern_Patagonia_Chile The southernmost bear: Pararctotherium (Carnivora, Ursidae, Tremarctinae) in the latest Pleistocene of Southern Patagonia, Chile. www.researchgate.net/publication/263381230_The_southernmost_bear_Pararctotherium_Carnivora_Ursidae_Tremarctinae_in_the_latest_Pleistocene_of_Southern_Patagonia_Chile A second upper incisor belonging to the tremarctine bear Pararc-totherium was recovered from latest Pleistocene deposits in Cueva de los Chingues, Magallanes, Chile (San Roman et al., 2000; Fig. 1). This is the southernmost record of an ursid in the world and one of the youngest records of Pararctotherium. The paleoenvironment of south-ern Patagonia in the latest Pleistocene (ca. 11,000 yBP) was a cold grassland. The Ursidae originated during the late Eocene in the Holarctic region and throughout its history has primarily been restricted to the Northern Hemisphere. Ursids twice dispersed into Africa (Hunt, 1996): the Hem-icyoninae in the early Miocene and Agriotherium in the late Miocene, with the latter reaching the southern tip of Africa (ca. 33Њ 43Ј S). The Tremarctinae is comprised of five genera: Plionarctos, consid-ered Pararctotherium to be a subgenus of Arctotherium. We regard both Arctotherium and Pararctotherium as valid, distinct genera based on the systematic and phylogenetic revision of South American fossil bears by LHS (e.g., Soibelzon, 2000, 2002; Soibelzon et al., 2000). Tremarctines dispersed into South America from North America at least twice. The oldest records of Arctotherium are early Pleistocene (Ensenadan age; Kraglievich and Ameghino, 1940; Berman, 1994; Soi-belzon and Bond, 1998; Soibelzon et al., 2001; Soibelzon, 2002). Tre-marctos, which lacks a fossil record in South America, probably crossed the Panamanian Isthmus in the latest Pleistocene or Holocene (Soibel-zon, 2002). South American fossil bears are primarily recovered from the Pampean Region (ca. 33Њ S), with isolated finds in Brazil, Bolivia, Chile, Venezuela, and Uruguay. Arctotherium latidens is the lone En-senadan tremarctine in South America. Following its extinction, tre-marctines were represented by several species of Pararctotherium dur-ing the middle to late Pleistocene (Bonaerian and Lujanian ages; Cione and Tonni, 1999). It was distributed widely across southern South America (Bolivia, Brazil, Argentina, Uruguay, and Chile) and persisted until the end of the Lujanian (Soibelzon and Bond, 1998; Soibelzon, 2002).
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Post by brobear on Jan 10, 2019 4:59:25 GMT -5
www.biolib.cz/en/taxonposition/id302092/ species Pampas Bear Pararctotherium pamparum Ameghino, 1904 † system Vitae - living organisms domain Eukaryota Whittaker & Margulis, 1978 - lifeforms with nucletic cells superregnum Unikonta system Opisthokonta Cavalier-Smith, 1987 kingdom Animalia Linnaeus, 1758 - animals subregnum Eumetazoa Butschli, 1910 divisio Bilateria Hatschek, 1888 - bilaterians subdivisio Deuterostomia - deuterostomes phylum Chordata Bateson, 1885 - chordates subphylum Vertebrata Cuvier, 1812 - vertebrates infraphylum Gnathostomata Zittel, 1879 - jawed vertebrates superclassis Tetrapoda Gaffney, 1979 - four-limbed vertebrates class Mammalia Linnaeus, 1758 - mammals subclass Theria Parker & Haswell, 1897 infraclass Eutheria Thomas Henry Huxley, 1880 order Carnivora Bowdich, 1821 - carnivores suborder Caniformia Kretzoi, 1938 - dog-like superfamily Ursoidea Fischer de Waldheim, 1817 family Ursidae Fischer von Waldheim, 1817 - bears subfamily Tremarctinae Merriam & Stock, 1925 genus Pararctotherium Ameghino, 1904 † species Pararctotherium pamparum Ameghino, 1904 - Pampas Bear †
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Post by King Kodiak on Jan 10, 2019 5:15:12 GMT -5
The weight of this bear is not listed nowhere correct Brobear?
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