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Post by brobear on Jan 10, 2019 5:41:12 GMT -5
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Post by brobear on Feb 1, 2019 4:46:00 GMT -5
Arctotherium angustidens.
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Post by brobear on Feb 1, 2019 4:48:55 GMT -5
1.8 meters is equal to 70.87 inches = 5 feet 11 inches shoulder height.
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Post by King Kodiak on Feb 20, 2019 5:31:34 GMT -5
My concern with this is why Angustidens is so low? The other 3 seem to have the correct normal max weight, but Angustidens seems to have more like an average weight correct? I mean it seems that way. Analyze this thread and see please. domainofthebears.proboards.com/thread/80/arctotherium
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Post by brobear on Feb 20, 2019 5:50:49 GMT -5
This was made by Tigerluver at wildfact.com/forum/ and he is a biologist ( and not biased for tigers as his name might imply ). The famous "biggest-ever bear" was a very old long-lived bear. Not a typical specimen of his species. Outside of that individual discovery, Arctodus simus proves taller that his South American cousin on average. However, you will notice that their weights are equal. Arctotherium was bigger-boned ( heavier, more massive build ).
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Post by brobear on Feb 20, 2019 6:19:51 GMT -5
Arctotherium angustidens - carnivora.net/index.php Arctotherium 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 King Kodiak on Feb 20, 2019 6:26:53 GMT -5
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).
Its a little confusing, are they talking about that one specimen found in Buenos Aires or in general?
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Post by brobear on Feb 20, 2019 6:33:04 GMT -5
Tigerluver used what methods he uses; using specific bone measurements. I am unsure of details. What I do know is, outside of this single incredible discovery, Arctodus simus was labeled as the biggest bear ever. The gigantic specimen is from the remains of a very old bear and not likely a typical specimen. On average, according to known fossils, Arctodus simus was the tallest of the two while Arctotherium angustidens was more robust - as heavy or perhaps heavier. Both bears ( IMO ) will continue to change within the biology books just as T-rex and Megalodon contyinually transform.
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Post by brobear on Feb 20, 2019 6:33:59 GMT -5
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). Its a little confusing, are they talking about that one specimen found in Buenos Aires or in general? Yes ( the one specimen ). Remember when Ursus maritimus tyrannus weighed 2,500 pounds?
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Post by brobear on Feb 20, 2019 9:20:53 GMT -5
That, my friend, is the problem with wiki. Constant changes made by individuals. Edit and add: carnivora.net/index.php by Taipan: Arctotherium angustidens
Arctotherium 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 King Kodiak on Feb 20, 2019 10:08:41 GMT -5
You are rigth Brobear, wiki might change. As we can see now, that statement is no longer there, they took it out. So maybe it was wrong after all. It was taken out for a reason. That means we have to go by what its updated. Close to 3500 lbs for that specimen as also every other site states. (Largest bear in history). The average weight of angustidens is still a mystery correct?
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Post by brobear on Feb 20, 2019 10:27:42 GMT -5
You are rigth Brobear, wiki might change. As we can see now, that statement is no longer there, they took it out. So maybe it was wrong after all. It was taken out for a reason. That means we have to go by what its updated. Close to 3500 lbs for that specimen as also every other site states. (Largest bear in history). The average weight of angustidens is still a mystery correct? The weights given to any prehistoric animal is merely educated guesswork. Also, where there are limited fossil remains, its difficult to say where the average lies. I'm forever looking for new data.
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Post by King Kodiak on Feb 20, 2019 11:09:09 GMT -5
You are rigth Brobear, wiki might change. As we can see now, that statement is no longer there, they took it out. So maybe it was wrong after all. It was taken out for a reason. That means we have to go by what its updated. Close to 3500 lbs for that specimen as also every other site states. (Largest bear in history). The average weight of angustidens is still a mystery correct? The weights given to any prehistoric animal is merely educated guesswork. Also, where there are limited fossil remains, its difficult to say where the average lies. I'm forever looking for new data. Yeah brobear absolutely, we dont have much data on these prehistoric animals. But what data can we expect from animals that lived 2 million years ago? Ha ha ha.
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Post by brobear on Feb 28, 2019 1:06:35 GMT -5
Arctotherium angustidens weight estimation: Started off at 4,500 pounds. Then dropped down to 3,500 pounds. Later, it took another nose-dive to 2,400 pounds. My thoughts: 3,000 pounds is a safe answer. Possibly a few hundred pounds too heavy or too light - but not off my much. 3,000 pounds is a safe bet.
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Post by King Kodiak on Feb 28, 2019 4:29:28 GMT -5
Arctotherium angustidens weight estimation: Started off at 4,500 pounds. Then dropped down to 3,500 pounds. Later, it took another nose-dive to 2,400 pounds. My thoughts: 3,000 pounds is a safe answer. Possibly a few hundred pounds too heavy or too light - but not off my much. 3,000 pounds is a safe bet. About 3000 lbs average weight you mean correct?
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Post by brobear on Feb 28, 2019 4:50:31 GMT -5
Arctotherium angustidens weight estimation: Started off at 4,500 pounds. Then dropped down to 3,500 pounds. Later, it took another nose-dive to 2,400 pounds. My thoughts: 3,000 pounds is a safe answer. Possibly a few hundred pounds too heavy or too light - but not off my much. 3,000 pounds is a safe bet. About 3000 lbs average weight you mean correct? No, the normal maximum. Remember that the gargantuan fossil remains were from a very large old bear. Not a typical specimen. The average mature male angustidens might weigh anywhere from 1500 to 2000 pounds - and that's a gigantic average. ( IMO ).
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Post by King Kodiak on Feb 28, 2019 5:22:13 GMT -5
About 3000 lbs average weight you mean correct? No, the normal maximum. Remember that the gargantuan fossil remains were from a very large old bear. Not a typical specimen. The average mature male angustidens might weigh anywhere from 1500 to 2000 pounds - and that's a gigantic average. ( IMO ). Yeah that one specimen was very old bear, also estimated over 11 feet tall. i believe that 3000 lbs is very reasonable for normal max weight. I believe the average could had been between 2000 and 2500 lbs, no less than 1 ton from all i have read. Arctodus Simus should be between 1500 and 2000 lbs, closer to 1500.
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Post by brobear on Mar 7, 2019 17:45:54 GMT -5
www.researchgate.net/publication/263381230_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. 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 Mar 8, 2019 11:44:21 GMT -5
†Arctotherium (Pararctotherium) pamparum Ameghino 1904 (bear) Osteichthyes - Carnivora - Ursidae
PaleoDB taxon number: 182931
Alternative combinations: Arctodus pamparus, Pararctotherium pamparum
Full reference: F. Ameghino. 1904. Nuevas especies de mamíferos, cretáceos y terciarios de la República Argentina [New species of mammals, Cretaceous and Tertiarty, from the Argentine Republic]. Anales de la Sociedad Cientifica Argentina 56–58:1-142
Belongs to Arctotherium (Pararctotherium) according to E. Trajano and H. Ferrarezzi 1995
See also Ameghino 1904
Sister taxa: Arctotherium (Pararctotherium) brasiliense, Arctotherium (Pararctotherium) enectum
Ecology: scansorial insectivore
Distribution: there are no occurrences of Arctotherium (Pararctotherium) pamparum in the database
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Post by brobear on Mar 8, 2019 11:46:38 GMT -5
bearsoftheworld.net/Arctotherium_latidens.asp The Arctotherium latidens, also known as the Argentine short-faced bear, was a large bear that lived in South America during the Ensenadan age (1.2 million to 800,000 years ago). It was an omnivorous creature, with males weighing up to 1,000 pounds. Arctotherium latidens is believed to have died out because of drastic changes in climate, and it was probably replaced by Pararctotherium pamparum. Because very few fossilized remains of this bear have been found, some scientists believe that it was not very populous.
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