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Post by King Kodiak on Sept 3, 2019 9:25:20 GMT -5
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Post by Deleted on Sept 4, 2019 0:38:01 GMT -5
Kodiak: I'm well aware of those 1500+ kg estimates for Arctotherium. All of those estimates originated from the Soibelzon 2011 paper (that i linked above). It's needed to keep in mind that the mass figures for extinct animals are not actual mass of the animals but are just estimates (since all you got are fragments of their bones). The 1500 kg estimate for Arctotherium was obtained by using a slightly different methodology than the 1000 kg estimates for Arctodus simus. If you use the methodology from Soibelzon 2011 and apply that to the measurements of Arctodus simus, it's very likely that you could also obtain a figure of 1500+ kg for Arctodus. On the other hand, if you use the methodology in Figueirido 2010 (which was used to obtain the 1000 kg mass for Arctodus) and apply that to the measurements of Arctotherium, you would probably only get a figure of ~1000 kg. My point here is that, if you look at the bone measurements, there aren't any indications to suggest that Arctotherium was a much bigger bear considering that, as i said in my previous post, the largest Arctotherium's humerus is slightly shorter than the largest Arctodus's humerus. The humerus of the Arctotherium is more robust (has greater transverse/mediolateral diameter), however, humerus robustness is a bad predictor for body mass in Ursids ( Figueirido 2010, Table 2). You are free to take that 1500 kg figure for Arctotherium as it is because it's still the 'official' estimate for Arctotherium. However, if you look at the bone measurements of these animals and put them next to one another, there aren't any reasons to believe Arctotherium was any bigger than Arctodus. The great difference in mass estimates here is merely from the use of different methodologies. Here is a picture of Arctodus's humerus www.nps.gov/kova/blogs/ice-age-mammal-bones-of-northwest-alaska-5.htmLike i said, isn't any smaller than that of Arctotherium
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Post by King Kodiak on Sept 4, 2019 6:36:10 GMT -5
The weights of these prehistoric bears were only estimated using some fossils, thats a fact and i could not agree more. We also have to take into consideration that Simus had a much larger range than Angustidens. It ranged from Mexico to Canada. Many more fossils of Simus were found, including in the La Brea tar pits. For Angustidens we only have that single specimen found, which it has been established that it was a very old male. I also agree with you on the methods used to calculate both species of bears. different methods will get you different results. Although as you said, the “official” estimated weight of that single Angustidens specimen was left at about 3500 lbs. who knows what would happen if they had found or find more specimens of Angustidens? Anything can happen.
so as far as the most bad-ass bear in history is concerned, i guess we can leave both Angustidens and Simus at the very top.
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Post by tom on Sept 4, 2019 12:30:43 GMT -5
All of those estimates originated from the Soibelzon 2011 paper (that i linked above). It's needed to keep in mind that the mass figures for extinct animals are not actual mass of the animals but are just estimates (since all you got are fragments of their bones). The 1500 kg estimate for Arctotherium was obtained by using a slightly different methodology than the 1000 kg estimates for Arctodus simus. If you use the methodology from Soibelzon 2011 and apply that to the measurements of Arctodus simus, it's very likely that you could also obtain a figure of 1500+ kg for Arctodus. On the other hand, if you use the methodology in Figueirido 2010 (which was used to obtain the 1000 kg mass for Arctodus) and apply that to the measurements of Arctotherium, you would probably only get a figure of ~1000 kg. My point here is that, if you look at the bone measurements, there aren't any indications to suggest that Arctotherium was a much bigger bear considering that, as i said in my previous post, the largest Arctotherium's humerus is slightly shorter than the largest Arctodus's humerus. The humerus of the Arctotherium is more robust (has greater transverse/mediolateral diameter), however, humerus robustness is a bad predictor for body mass in Ursids ( Figueirido 2010, Table 2). You are free to take that 1500 kg figure for Arctotherium as it is because it's still the 'official' estimate for Arctotherium. However, if you look at the bone measurements of these animals and put them next to one another, there aren't any reasons to believe Arctotherium was any bigger than Arctodus. The great difference in mass estimates here is merely from the use of different methodologies. www.nps.gov/kova/blogs/ice-age-mammal-bones-of-northwest-alaska-5.htmLike i said, isn't any smaller than that of Arctotherium Question: Could these methodologies be used to estimate size on extant Bears? Basically what I'm saying is we already know roughly the average weights and size of various extant Bear species, but have bones from extant Bears actually been used to test the methodologies accuracy? Maybe it's not as simple as that dunno. If we can prove accuracy on extant Bears with current methodologies then i see no reason why they would not be as accurate using skeletal remains of extinct Bears. I would think by doing similar studies on extant Bears one could determine which methodology for testing is the more accurate would it not?
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Post by brobear on Oct 26, 2019 3:39:18 GMT -5
According to "tigerluver" over at Wildfact, ( a true Biologist ) these two giant short-faced bears were of equal size. The Pleistocene grizzly which generally weighed roughly 700 pounds ( 318 kg ) was only half the giant's size. *I will edit and add, to stay on topic, SIZE is a powerful advantage. At equal head-and-body length, a grizzly would be stronger and heavier than either giant short-faced bears. But alas, the giants were...well... giants.
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Post by brobear on Jul 4, 2020 5:37:02 GMT -5
Biggest of the Biggest Bears of the genus Ursus is a contest between the Pleistocene Steppe Bear ( Ursus arctos priscus ) and the Gamssulzen Cave bear ( Ursus Kanivetz / Ursus Ingressus ). Both of these bears were bigger and heavier than either the Kodiak bear or even the polar bear. *Also in this contest is Ursus ( maritimus ) tyrannus ) which was probably a brown bear yet possibly a polar bear.
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Post by brobear on Nov 2, 2020 4:30:03 GMT -5
Of all of the subfamily Ursinae ( Ursus bears ) we are still left with three top contenders for the biggest bear award. 1- Ursus Kanivetz / Ursus Ingressus 2- Ursus arctos priscus 3- Ursus Maritimus Tyrannus
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Post by OldGreenGrolar on Nov 2, 2020 6:35:18 GMT -5
800 kg as a possible size of a big black grizzly. 800 kilograms is equal to 1,763.70 pounds (avoirdupois) That is slightly heavier than the exceptionally large male polar bears which are too heavy to be lifted. And since the heaviest Kodiak bear surpasses the heaviest polar bear, it is possible that the heaviest Ussuri brown bear can surpass the heaviest Kamkatcha brown bear.
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Post by OldGreenGrolar on Nov 2, 2020 6:36:23 GMT -5
Of all of the subfamily Ursinae ( Ursus bears ) we are still left with three top contenders for the biggest bear award. 1- Ursus Kanivetz / Ursus Ingressus 2- Ursus arctos priscus 3- Ursus Maritimus Tyrannus Isn’t Tyrannus actually a brown bear?
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Post by King Kodiak on Nov 2, 2020 10:44:10 GMT -5
Of all of the subfamily Ursinae ( Ursus bears ) we are still left with three top contenders for the biggest bear award. 1- Ursus Kanivetz / Ursus Ingressus 2- Ursus arctos priscus 3- Ursus Maritimus Tyrannus Isn’t Tyrannus actually a brown bear? Most likely yes, most scientists think so. Its just not officially confirmed yet. Tyrannus might just be Ursus arctos priscus or even another brown bear subspecies similar to priscus.
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Post by brobear on Nov 2, 2020 11:17:55 GMT -5
Reply #3... www.polarresearch.net/index.php/polar/article/viewFile/6131/6810The Kew Bridge find is special in that it is an ulna of a very large animal, considerably larger than present-day polar bears. Kurtén (1964) assigned it to a polar bear subspecies, Ursus maritimus tyrannus. The Kew Bridge specimen has recently been reinvestigated by scientists at London’s Natural History Museum, and they are now confident that the Kew animal was a type of brown bear, U. arctos (Andy Currant, pers. comm. 2008). reply #15.... That said, it is true that these British bears were isolated for a considerable amount of time, from about 87.22-66.8 thousand years ago, based on the dating of this period, spanning roughly 20,000 years. From this; my thoughts are: a group of steppe brown bears - Ursus arctos priscus - were isolated from others of their kind for 20,000 years certainly creating a new subspecies. I am waiting and expecting a name-change to Ursus arctos tyrannus. www.history.com/shows/the-hunt/articles/kodiak-bear-fact-sheet Kodiak bears are a unique subspecies of the brown or grizzly bear (Ursus arctos middendorffi). They live exclusively on the islands in the Kodiak Archipelago and have been isolated from other bears for about 12,000 years. *So, whether U.m.tyrannus was a brown bear or a polar bear, he was separated from all other bears for roughly 8,000 year longer than the Kodiak bear has been separated. I believe that this makes it an absolute certainty that, even if U.m.tyrannus proves to be a brown bear, he was a separate subspecies all his own and not Ursus arctos priscus. Ursus maritimus tyrannus is probably a brown bear but not likely a Steppe bear.
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Post by King Kodiak on Nov 2, 2020 11:34:41 GMT -5
Reply #104: that is a great find brobear. You are right, if Tyrannus was separated for so long, then it should be a different subspecies, just like Kodiaks. But time will tell if this is confirmed.
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Post by Deleted on Nov 3, 2020 7:33:53 GMT -5
Isn't the South-american short faced bear the biggest bear?
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Post by King Kodiak on Nov 3, 2020 7:58:13 GMT -5
Isn't the South-american short faced bear the biggest bear? Yes, but he is from another bear subfamily, Tremarctinae.
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Post by brobear on Nov 8, 2020 14:32:45 GMT -5
Reply #104: that is a great find brobear. You are right, if Tyrannus was separated for so long, then it should be a different subspecies, just like Kodiaks. But time will tell if this is confirmed. Being marooned on an island for 20,000 years ( 8,000 years longer than the Kodiak bear to date ) separated from all other bears pretty-much seals the deal ( IMO ) that U.m.tyannus was his own subspecies. What still needs to be confirmed is brown bear or polar bear. Also unanswered; who was the biggest...The "tyrant sea bear", the Steppe bear, or the Gamssulzen Cave bear?
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Post by King Kodiak on Nov 8, 2020 14:44:49 GMT -5
That is a great question. Please dont make go crazy going over all those individual threads, ha ha ha. We have always said that the largest bear of the Ursus genus was the Steppe brown bear.
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Post by King Kodiak on Nov 8, 2020 15:01:17 GMT -5
If i remember correctly, from all the general info on weights that we have, all 3 bears are very close in the weight range. The Steppe brown bear, the Tyrant sea bear, and the Gamssulzen Cave bear.
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Post by brobear on Nov 8, 2020 15:08:08 GMT -5
If i remember correctly, from all the general info on weights that we have, all 3 bears are very close in the weight range. The Steppe brown bear, the Tyrant sea bear, and the Gamssulzen Cave bear. Yeah; they're all three probably so close that, even if we had living populations of them, it would be too close to be certain. Like saltwater crocodile compared with Nile crocodile. Reports say that the salty is bigger on average. But according to Pckts; the record-sized individual crocodile was a Nile. Truth is, they're so close that its kind of redundant to claim one bigger than the other. Same holds true for great Indian rhino and African white rhino. Battle of the Tanks: Indian Rhinoceros vs White Rhinoceros Nile Crocodile (right) vs Saltwater Crocodile (left)
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Post by brobear on Dec 27, 2020 14:08:22 GMT -5
Created by: theundertaker45
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Post by brobear on Dec 27, 2020 19:31:09 GMT -5
Since we do not have a large population of living Arctodus simus nor Arctotheium angustidens, it is thus not only impossible to even estimate an average weight with any true accuracy, but also impossible to say with any certainty which of these two giants were the biggest of the big bears. We can be certain, however, that each was the king of his own domain; each during his own time.
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