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Post by King Kodiak on Nov 16, 2019 7:13:33 GMT -5
exactly: the normal max weights. ( cannot read the site given - wants me to sign up for something ). Yeah sure i agree, 2400 lbs would be the normal max weight of Angustidens, but i was talking about that single specimen found in Buenos aires estimated to be about 3500 lbs by that expert paleontologist.
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Post by brobear on Nov 16, 2019 7:15:27 GMT -5
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Post by King Kodiak on Nov 16, 2019 7:20:29 GMT -5
1750 KG=3850 LBS BY ROMAN UCHYTEL, VERY RELIABLE.
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Post by brobear on Nov 16, 2019 7:32:15 GMT -5
shaggygod.proboards.com/thread/956/simus-yuk-angustidens-tyrannus Ulna comparison between A. angustidens vs. U.m.tyrannus Ursus maritimus tyrannus (B.M. 24361 Kew Bridge specimen) L, total length of the ulna. PD, greatest proximal diameter, measured anteroposteriorly from the tip of the coronoid process to Margo dorsalis. SD, inner diameter of the semilunar notch, measured vertically. BS, minimum transverse breadth of shaft. This is in the distal portion of the shaft, at some distance above the capitulum. The extreme constriction lies close to the capitulum in the Brown Bear and the spelaeids, but higher on the shaft in the Polar Bears, including the Kew specimen. 1 L, length; PD, maximum proximal diameter; SD, inner diameter of semilunar notch; BS, minimum shaft diameter. Ursus maritimus tyrannus Ulna measurements L: e485 PD: a95 SD: 44 BS1: 27.6 Ursus maritimus tyrannus (Plate # 2 Ulnae) Kurten, Bjorn 1964, The evolution of the Polar Bear Ursus maritimus Phipps.
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Post by brobear on Nov 16, 2019 7:32:54 GMT -5
Continued: Arctotherium angustidens
Ulna measurements
Greatest length: Right; Left, 570.
Greatest width of olecranon processWidth from posterior border to tip of coronoid process: Right, 108; Left, 109.
Least distance from sigmoid notch to posterior border: Right, 66; Left, 70.
Greatest diameter of distal epiphyses: Right, 63; Left, 62.5.
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Post by brobear on Nov 16, 2019 7:34:08 GMT -5
Follow up on Ursus maritimus tyrannus (B.M. 24361 Kew Bridge specimen):
B.M. No. 24361 is a bear ulna of gigantic proportions. The specimen is well preserved, but the distal epiphyse is missing, so that the bone evidently belonged to a subadult animal. There is also slight damage to the distal end of the diaphyse, the olecranon, and the coronoid process, but the essential characters are well preserved. The fragment has a total length of about 440 mm. as preserved. In a very large subadult recent Polar Bear (U.Z.I. No. 3), the length without distal epiphyse is 387 mm., and the total length 428 mm. Thus the full length of the fossil bone may be estimated at a minimum of 485 mm. As far as I know this is the longest ursine ulna on record. The large Pleistocene tremarctines (Arctodus) of the Americas were unusually long-legged bears, and in some cases their limb bones attain similar or greater dimensions. The maximum record from Potter Creek Cave in northern California is 446 mm. (U.C. No. 3426), and from Rancho La Brea, Los Angeles, 475 mm. (L.A.C.M. No. Z32); and a tremendous specimen from the Irvingtonian, or Californian Middle Pleistocene, attains the almost incredible length of 591 mm (Kurten, 1964).
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Post by King Kodiak on Nov 16, 2019 7:35:11 GMT -5
So in reality, i dont see downsizing of that single Angustidens specimen anywhere, all the sites (which copy each other yes) state it was around 3500 to 3800 lbs. I have to go by that. Unless any of these debators who "downsize" prehistoric animals actually saw and studied that skeleton and humerus in person. 😀
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Post by brobear on Nov 16, 2019 7:38:02 GMT -5
and a tremendous specimen from the Irvingtonian, or Californian Middle Pleistocene, attains the almost incredible length of 591 mm (Kurten, 1964). grrraaahhh says: As I understand it: UVP015 = 591 mm (Utah specimen) RE: 591 mm ulna length, it is confirmed.
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Post by brobear on Nov 16, 2019 7:40:05 GMT -5
Using Kurten's weight estimate of 590-630 kg for the large specimen from Hay Springs, we calculated the weight of the Salt Lake County specimen to be in the range of 620-660 kg. This weight calculation was based on Kurten's (1967) estimates of "fairly lean individuals" but conveys an idea of the large size of these animals. Fattened bears might weigh several tens of kilograms more than this estimate (Nelson & Madson 1983). However.... The specimen described here has an estimated body mass ranging from 983 to 2,042 kg depending on the equations considered (Tables 3 and 4). The highest predicted value is probably unrealistic, although the size of this individual is much higher than other known specimens (see Table 5). All predicted body masses based on humeral measurements are shown in Table 3. The mean and median (considering all equations) are 1,588 and 1,749 kg respectively. Thus, we suggest that the body mass of this gigantic bear was between these two values. To our knowledge, this makes the A angustidens described here the largest known bear, and probably the most powerful terrestrial carnivoran of the late Cenozoic (Soibelzon & Schubert 2011).
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Post by brobear on Nov 16, 2019 7:41:12 GMT -5
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.
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.
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.
"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.
"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.
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Post by brobear on Nov 16, 2019 7:43:03 GMT -5
Largest recorded North American Arctotherium fossils.
Ulna: 591 mm (Ivringtonian, Alameda County, CA).
Ulna measurements:
UC 40086:
A: - B: 105 C: 62 D: - E: -
A. Greatest Length. B. Proximal diameter from tip of coronoid progress to Margo dorsalis. C. Smallest diameter from bottom of semi circular notch to Margo dorsalis.. D. Inner diameter of semi circular notch. E. Least transverse diameter of shaft, above capitulum.
UC 44686:
A: 591 B: - C: 65 D: 47 E: 35.2
A. Greatest Length. B. Proximal diameter from tip of coronoid progress to Margo dorsalis. C. Smallest diameter from bottom of semi circular notch to Margo dorsalis.. D. Inner diameter of semi circular notch. E. Least transverse diameter of shaft, above capitulum.
Extra (largest femur) ......
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Post by brobear on Nov 16, 2019 7:43:42 GMT -5
emur Measurements:
UC 44687
A. 678 B. a165 C. 77 D. 62 E1. 134
A. Greatest Length. B. Greatest proximal width. C.Caput diameter. D. Least transverse width of shaft. E1. Greatest distal width over epicondyles.
Source: Kurten (1967).
Stay tuned...there are more large North American specimens.
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Post by brobear on Nov 16, 2019 7:45:24 GMT -5
Hello, thanks for theses good informations. But i would like understand some points please:
First, according to your informations,
tyrannus ulna has a total length of 485mm. Arctotherium ulna has a total length of 570mm. Arctodus simus UVP015 ulna has a total length of 591 mm.
I don't understand, all people say that tyrannus is taller and bigger than arctodus, nevertheless ulna arctodus is much longer than ulna tyrannus... Do you know what is the height of UVP015 when it was standing on his legs? Same question about tyrannus please.
Then, do you know measurements about skull of arctotherium (largest males)? *In a very large subadult recent Polar Bear (U.Z.I. No. 3), the length without distal epiphyse is 387 mm., and the total length 428 mm This polar bear may reach 3.3 meters standing on his legs, how do you explain that a polar bear which has an ulna of 440mm is as tall as arctotherium angustidens which has an ulna of 570mm...?
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Post by King Kodiak on Nov 16, 2019 7:45:41 GMT -5
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Post by brobear on Nov 16, 2019 7:50:53 GMT -5
So in reality, i dont see downsizing of that single Angustidens specimen anywhere, all the sites (which copy each other yes) state it was around 3500 to 3800 lbs. I have to go by that. Unless any of these debators who "downsize" prehistoric animals actually saw and studied that skeleton and humerus in person. 😀 Most of this will soon be transported over to the topic Arctotherium. I think you are right. What I was remembering was the first report gave a rough estimate of 4000+ pounds but was downsized to 3500 or 3800 pounds. But I also think that tigerluver ( I know you love that handle ) is close to accurate with their normal max-weights ( 2400 pounds ). Averages would probably be around 1600 to 1800 pounds ).
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Post by brobear on Nov 16, 2019 7:52:02 GMT -5
Check out ulna lengths reply #25.
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Post by King Kodiak on Nov 16, 2019 8:04:04 GMT -5
Check out ulna lengths reply #25. "Arctotherium ulna has a total length of 570mm" Yeah, that is a huge ulna bro.
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Post by brobear on Nov 16, 2019 8:07:57 GMT -5
Grrraaahhh... FYI .... there are other LARGE North American Arctotherium fossil specimens. I am in the process of organizing these data and plan to post relating data including photos for comparisons in the not too far future. UVP 015 Lake Bonville, Utah Specimen & Material:
Femoral measurements (mm)
UVP 015/1
Greatest length: 723 Greatest proximal width: 191 Caput diameter: - Least transverse width of shaft: 64 Greatest distal width over condyles: 152
Tibial measurements (mm)
UVP 015/2
Greatest length: 524 Greatest proximal width: 152 Least width of shaft: 50.15 Greatest distal width: 119
UVP 015/3
Greatest length: 522 Greatest proximal width: 155 Least width of shaft: 50 Greatest distal width: 119
Width of shaft in percent of total length of the tibia in Arctodus simus
Arctodus simus (Salt Lake County)
Number of Specimens: 2 Range: 9.6 Mean: 9.6 Measurements (mm) of pelvis in Arctodus simus.
UVP 015/7
Ilium, length from rim of acetabulum to anterior border: 273± Ilium, greatest width: 239± Ilium, least width of neck in front of acetabulum: 84 Acetabulum, transverse diameter: - Obturator foramen, greatest anteroposterior diameter: 127 Obturator foramen, greatest dorsoventral diameter: -
Measurements (mm) of vertebral centra in Arctodus simus
UVP 015/4 L2?
Length: 66 Width: 93 Depth: 66
UVP—Utah Vertebrate Paleontology, Utah Division of State History
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Post by brobear on Nov 16, 2019 8:09:47 GMT -5
Grrraaahhh: I would say there are a handful of North American GSFB specimens that are in the ballpark range of A.angustidens as it relates to size. Some of them have a longer ulna, some of them have a longer humerus.
RE: U.m. tyrannus, its fossil history stops with its ulna. There are varying debates about this beast, some argue the bear was more brown bear than polar bear, some think the fossil ulna belonged to a very large brown bear, and of course the original theory that the bear was the first form of polar bear.
Personal note, there's a lot of technical work I have to do this week as they relate to my computers which is impacting my ability to forum post (less so).
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Post by brobear on Nov 16, 2019 8:11:25 GMT -5
Grrraaahhh: 591 mm is correct. I actually have fossil photos of the Californian specimen including the ulna but my hope/plans were to obtain fossil photos of another large male Nebraska (Hays Spring, NE) GSFB specimen which are housed in NYC. The femur measurement values for this Nebraska specimen rank it 3rd largest for existing GSFB remains. Collectively, if one includes the large Cass County, NE GSFB humerus fossil KUVP C-2427 - altogether (from the photos obtained here as well as those from the literature) we have photos of the three largest GSFB humerus, femur, and ulna fossils.
The specimen MLP 35-IX-26 described in Soibelzon & Schubert (2011) has a left ulna 570mm long.
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