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Post by brobear on May 1, 2017 3:33:01 GMT -5
Kolponomos is an extinct genus of marine bears which existed from the Hemingfordian age to the Aquitanian age of the Miocene epoch, about 20 million years ago.
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Post by Polar on Apr 18, 2018 14:06:12 GMT -5
Kolponomos wasn't really a bear as much as it was an "arctoid" either...more like an evolutionary offshoot off of the earliest bear/pinniped-like ancestors.
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Post by brobear on Apr 18, 2018 17:09:56 GMT -5
www.sciencedaily.com/releases/2016/03/160301211334.htm Extinct otter-like 'marine bear' might have had a bite like a saber-toothed cat Biomechanical modeling suggests that Kolponomos likely used anchor-biting to pry hard-shelled invertebrates Date: March 1, 2016 Source: American Museum of Natural History Summary: New research suggests that the feeding strategy of Kolponomos, an enigmatic shell-crushing marine predator that lived about 20 million years ago, was strangely similar to a very different kind of carnivore: the saber-toothed cat Smilodon. Scientists have shown that even though the two extinct predators likely contrasted greatly in food preference and environment, they shared similar engineering in jaw structure. New research suggests that the feeding strategy of Kolponomos, an enigmatic shell-crushing marine predator that lived about 20 million years ago, was strangely similar to a very different kind of carnivore: the saber-toothed cat Smilodon. Scientists at the American Museum of Natural History used high-resolution x-ray imaging and computerized biting simulations to show that even though the two extinct predators likely contrasted greatly in food preference and environment, they shared similar engineering in jaw structure, suitable for anchoring against prey with the lower jaw and forcefully throwing the skull forward to pry loose its food. The study is published today in the journal Proceedings of the Royal Society B. The only known specimens of Kolponomos--primarily skulls and teeth of two species--were recovered from ancient marine deposits along the Pacific coast of Oregon, Washington, and possibly Alaska. Because of its peculiar morphology and the small number of fossils, the animal's place in the evolutionary tree remains a mystery. "When Kolponomos was first described in the 1960s, it was thought to be a raccoon relative," said Camille Grohé, a National Science Foundation and Frick Postdoctoral Fellow in the American Museum of Natural History's Division of Paleontology and a co-author on the new paper. "But later research on the skull base led some to think it might be a seal or a bear relative instead, and studies of its teeth show that they are very similar in both shape and wear to the teeth in sea otters." Sea otters pry their prey--hard-shelled marine invertebrates like clams and mussels--off of surfaces using their hands and rock tools, then crush the shells with their teeth or against their chests, again using tools. By studying Kolponomos fossil material from the National Museum of Natural History in Washington, D.C., and comparative specimens from the American Museum of Natural History, the research team originally set out to test if the extinct predator used otter-like shell-crushing to eat. But the scope of the research expanded after Grohé's collaborator Z. Jack Tseng noticed something curious in parallel to work he was conducting on the saber-toothed cat Smilodon. "I started seeing a great deal of similarity between the jaws of Kolponomos and Smilodon," said Tseng, a National Science Foundation and Frick Postdoctoral Fellow in the American Museum of Natural History's Division of Paleontology and the lead author on the new paper. "Both of them have a distinctive profile with a deep jaw bone that tapers off toward the back, and both have an expansion of the mastoid processes and the skull's back surface, suggesting large attachment sites for muscles that let the animal move its head powerfully but with control. We definitely didn't expect to bring Smilodon into this study of feeding in a clam-eating marine carnivore, but that's what we ended up doing." At the Museum's Microscopy and Imaging Facility, the researchers used computed tomography (CT) to scan the skulls of Kolponomos and six other carnivores: Smilodon, grey wolf, sea otter, river otter, brown bear, and leopard. They then used computerized methods to build sophisticated biomechanical models to look at how efficiently the animals could perform various bites, including the jaw-anchored killing shear-bite that is characteristic of saber-tooth cats. They found that the jaw mechanics of Kolponomos and Smilodon are more similar to each other than to any of the other animals in the study, pointing to a unique feeding strategy in addition to the previous idea that Kolponomos might have crushed its prey like sea otters do today. Taken together, the researchers suggest that Kolponomos might have pried prey off of rocks with its lower jaw, swung its skull forward to dislodge it, and then crunched it with its chewing teeth. "Our biomechanical data show that the chewing bites of sea otters and Kolponomos are not very similar," Tseng said. "They probably still have an overlapping diet based on tooth wear, but their evolutionary solutions for getting to those hard-shelled animals are dramatically different." The researchers stress that this finding does not imply shared ancestry between Kolponomos and Smilodon, but rather an intriguing case of convergence--the independent evolution of similar traits. "This innovative study, showing unexpected feeding similarities between such wildly distinct carnivores, could only happen by applying new technologies to understand specimens from some of the world's greatest archives of ancient life," said John J. Flynn, a curator in the Museum's Division of Paleontology and Dean of the Richard Gilder Graduate School, also an author on this paper. This work was funded by the U.S. National Science Foundation grant # DEB-1257572 and the American Museum of Natural History's Frick Postdoctoral Fellowships. The authors have dedicated this study to the memory of Museum artist Chester Tarka, who illustrated Kolponomos newportensis. Story Source: Materials provided by American Museum of Natural History. Note: Content may be edited for style and length.
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Post by Deleted on May 13, 2019 9:53:49 GMT -5
Kolponomos is an extinct genus of marine bears which existed from the Hemingfordian age to the Aquitanian age of the Miocene epoch, about 20 million years ago. Well the polar bear isn't the only marine bear.
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Post by brobear on Oct 26, 2019 9:26:17 GMT -5
The "Otter Bear": www.bearsoftheworld.net/kolponomos.asp
Kolponomos was a genus of marine bears that existed approximately 20 million years ago during the Miocene epoch. There are two known species in the genus (Kolponomos clallamensis and Kolponomos newportensis). All specimens have been found in near-shore marine rocks. A partial skull and jaw which was found on the Olympic Pennisula of Washington was first described in 1960 by paleontologist Ruben A Stirton as a large marine procyonid. However, a specimen found in two pieces near Newport, Oregon, in 1969 and 1977, proved the genus was related to ancestors of bears.
Kolponomos had downturned snouts and broad, heavy molars that would have been well suited to a diet of hard-shelled marine invertebrates.
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Post by brobear on Oct 26, 2019 9:39:38 GMT -5
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Post by brobear on Oct 26, 2019 9:41:35 GMT -5
www.eartharchives.org/articles/killer-bite-of-the-otter-bear/ Killer bite of the otter-bear. One of the most unusual marine mammals of all time was Kolponomos, the “otter-bear”. Details of this enigmatic animal have remained quite a mystery for many years since its discovery. Now, scientists have finally figured out the secret behind the otter-bear’s deadly bite, and just how it managed to survive.
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Post by OldGreenGrolar on Oct 26, 2019 16:26:41 GMT -5
brobear. Do you know the weights of the kolponomos? Thanks.
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Post by OldGreenGrolar on Oct 26, 2019 16:52:32 GMT -5
Thanks. I was expecting the kolponomos to be larger than that (at least polar bear size) but anyway this animal is still among my favourite now.
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Post by brobear on Nov 4, 2019 9:48:23 GMT -5
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Post by brobear on Nov 5, 2019 12:34:02 GMT -5
en.wikipedia.org/wiki/Amphicynodontinae Amphicynodontinae is a probable clade of extinct arctoids. While some researchers consider this group to be an extinct subfamily of bears, a variety of morphological evidence links amphicynodontines with pinnipeds, as the group were semi-aquatic otter-like mammals. In addition to the support of the pinniped–amphicynodontine clade, other morphological and some molecular supporting bears being the closest living relatives to pinnipeds. According to McKenna and Bell (1997) Amphicynodontinae are classified as stem-pinnipeds in the superfamily Phocoidea. Fossils of these mammals have been found in the Holarctic region of the planet. Systematics Subfamily †Amphicynodontinae (Simpson, 1945) †Amphicticeps (Matthew and Granger, 1924) †Amphicticeps makhchinus (Wang et al., 2005) †Amphicticeps dorog (Wang et al., 2005) †Amphicticeps shackelfordi (Matthew and Granger, 1924) †Parictis (Scott, 1893) †Parictis primaevus (Scott, 1893) †Parictis personi (Chaffee, 1954) †Parictis montanus (Clark & Guensburg, 1972) †Parictis parvus (Clark & Beerbower, 1967) †Parictis gilpini (Clark & Guensburg, 1972) †Parictis dakotensis (Clark, 1936) †Kolponomos (Stirton, 1960) †Kolponomos newportensis (Tedford et al., 1994) †Kolponomos clallamensis (Stirton, 1960) †Allocyon (Merriam, 1930) †Allocyon loganensis (Merriam, 1930) †Pachycynodon (Schlosser, 1888) †Pachycynodon tedfordi (Wang & Qiu, 2003) †Pachycynodon tenuis (Teilhard de Chardin, 1915) †Pachycynodon filholi (Schlosser, 1888) †Pachycynodon boriei (Filhol, 1876) †Pachycynodon crassirostris (Schlosser, 1888) †Amphicynodon (Filhol, 1881) †Amphicynodon mongoliensis (Janovskaja, 1970) †Amphicynodon teilhardi (Matthew and Granger, 1924) †Amphicynodon typicus (Schlosser, 1888) †Amphicynodon chardini (Cirot and De Bonis, 1992) †Amphicynodon cephalogalinus (Teilhard, 1915) †Amphicynodon gracilis (Filhol, 1874) †Amphicynodon crassirostris (Filhol, 1876) †Amphicynodon brachyrostris (Filhol, 1876) †Amphicynodon leptorhynchus (Filhol, 1874) †Amphicynodon velaunus (Aymard, 1846)
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Post by brobear on Nov 5, 2019 12:38:54 GMT -5
Scientific classificatione Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Carnivora Family: Ursidae Subfamily: †Amphicynodontinae Simpson, 1945 †Amphicticeps †Parictis †Kolponomos †Allocyon †Pachycynodon †Amphicynodon †Wangictis *Note: Family Ursidae.
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Post by brobear on Nov 7, 2019 5:40:55 GMT -5
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Post by brobear on Nov 10, 2019 3:52:59 GMT -5
prehistoric-fauna.com/Kolponomos-clallamensis Kolponomos clallamensis Order: Carnivora Family: Ursidae Dimensions: length - 1,2 m ( 4 feet ), height - 70 сm ( 2 feet 4 inches ), weight - 80 kg ( 176 pounds ). Temporal range: Early Miocene of North America (~23 – 20,6 Ma years ago) Kolponomos is an extinct genus of marine bears which existed from the Hemingfordian age to the Aquitanian age of the Miocene epoch, about 20 million years ago. It was described in 1960 by Ruben A. Stirton, a paleontologist at the American Museum of Natural History, from a partial skull and jaw found on the Olympic Peninsula. Stirton thought the fossil was a large marine procyonid, but a specimen found in two pieces by fossil collector Douglas Emlong near Newport, Oregon, in 1969 and 1977, proved the genus was related to ancestors of bears. Since that time, one other Kolponomos fossil has been discovered, in the Aleutian Islands, bringing the total number of specimens to three. Kolponomos had downturned snouts and broad, heavy molars that would have been suited to a diet of hard-shelled marine invertebrates, and their narrow snouts and anteriorly directed eyes indicate that they would have been able to view objects directly in front of their heads. Large neck muscle attachments and robust foot bones combine with these features to suggest that Kolponomos filled a unique niche among marine carnivores, approached today only by the unrelated sea otter. Due to the lack of a complete skeleton, however, it is difficult to make inferences about this group's other adaptations.
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Post by brobear on Nov 10, 2019 3:58:28 GMT -5
Kolponomos newportensis Kolponomos newportensis was described in 1994 by R. Tedford, L. Barnes and Clayton E. Ray. It is represented by single specimen: a nearly complete skull, jaw and post-cranial bones found in a concretion of sediment. The concretion was discovered in two pieces by fossil collector Douglas Emlong near Newport, Oregon, the first in 1969 and the second, eight years later, in 1977. Because the concretion had been hardened so much by tectonic stress, the paleontological laboratory at the Smithsonian Institution considered them "the most difficult materials ever encountered by our laboratory., "and a combination of techniques proved essential to its extraction and preparation, which lasted two decades. Discovery of K. newportensis disproved the earlier hypothesis that the genus was related to ancestors of raccoons, and showed instead that it is an early but unusual bear relative closely tied to the origin of pinnipeds.
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Post by brobear on Nov 14, 2019 4:38:52 GMT -5
Kolponomos wasn't really a bear as much as it was an "arctoid" either...more like an evolutionary offshoot off of the earliest bear/pinniped-like ancestors. I have to agree with Polar here. As with the giant panda, it had been argued for decades whether the giant panda was a bear or a relative to the raccoon. This argument ended with DNA evidence stating that the giant panda is a bear. ( I was wrong on this one ). Scientist are in disagreement about just what Koponomos really was. I agree with Polar... an ancient bear relative and possibly the ancestor of our pinnipeds... or a close relative of both bears and pinnipeds.
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Post by King Kodiak on Nov 14, 2019 5:40:47 GMT -5
Kolponomos wasn't really a bear as much as it was an "arctoid" either...more like an evolutionary offshoot off of the earliest bear/pinniped-like ancestors. I have to agree with Polar here. As with the giant panda, it had been argued for decades whether the giant panda was a bear or a relative to the raccoon. This argument ended with DNA evidence stating that the giant panda is a bear. ( I was wrong on this one ). Scientist are in disagreement about just what Koponomos really was. I agree with Polar... an ancient bear relative and possibly the ancestor of our pinnipeds... or a close relative of both bears and pinnipeds. I have to agree with both of you. Although up to now, it is still officially in the family of Ursidae.
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Post by brobear on Dec 1, 2019 16:55:40 GMT -5
Kolponomos (Kolponomos newportensis) North America. Miocene. Length -1,2 m, height - up to 1 m, weight - up to 100 kg. The name of the kind means is "the inhabitant of the bay". it is likely that this predator lived on the coast It is believed that he is a relative of the ancestors of modern bears, although the system position is still completely not connected (first vídnosili to Some features of the construction of the cruncher and teeth bring down these "Sea Vidropodíbnih Bears" with kalanami and lastonogimi. Distinctive teeth allow you to assume that the kolponom was harčuvavsâ by the molluscs, which was cut off from
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Post by OldGreenGrolar on Dec 1, 2019 19:07:08 GMT -5
The kolponomos still has the bulky built and powerful forearms a bear has. I am not surprise if a kolponomos is actually very strong for its size.
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Post by King Kodiak on Dec 7, 2019 6:24:53 GMT -5
The best known skull of the rare beach-dwelling bear, Kolponomos clallamensis Stirton , 1960 (in left lateral and ventral views), found in the early Miocene Clallam Formation at Clallam Bay by Albin Zukofsky II. In both views the nose is pointing toward the left. A diet of hard-shelled, rockdwelling intertidal invertebrates is suggested by the forwarddirected eyes that would have allowed stereoscopic vision, the protruding snout with elongate incisors and canines that could have acted like pliers, the large mastoid and paroccipital processes at the back of the skull for attachment of strong neck muscles , and the broad, flat cheek teeth forming an efficient grinding mechanism. (Natural History Museum of Los Angeles County catalog no. 131148.) www.researchgate.net/figure/The-best-known-skull-of-the-rare-beach-dwelling-bear-Kolponomos-clallamensis-Stirton_fig13_301886926
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