Post by grrraaahhh on Mar 27, 2010 8:05:38 GMT -9
Administrative Update: Hi everyone, I wanted to tweak this thread a bit. I've decided to clearer separate Extant bear news from the Prehistoric bear news. Some of the stories/posts you are reading will be repeat ones from earlier threads but henceforth all relating Prehistoric & Early Bear News info will be placed here.
Bear Hunting Altered Genetics More Than Ice Age Isolation
www.sciencedaily.com/releases/2007/11/071126115307.htm
Four complete skulls and jaws of a Pleistocene bear species called Arctotherium, that disappeared 11,300 years ago, were found by aquatic archaeologists in a submerged cave on the Yucatan peninsula in Mexico.
The 25-30 cm long skulls discovered at 42 meters underwater, belong to two adult bears - one of each sex - and two bears that had not reached full maturity.
The discovery was made by Guillermo de Anda Alanis and his team from the Yucatan Autonomous University, while they were diving in a cavern, as part of the project authorized by the National Institute of Anthropology and History (INAH) “El Culto al Cenote en el Centro de Yucatan†(Cult to Cenote in Central Yucatan).
Guillermo de Anda Alanis said that the fossils were found between the towns of Sotuta and Homun, in Yucatan, spread on a 120 meters diameter surface.
The four skulls seem to belong to a family of bears of the same species, because the 2 adult skulls belonged to a male and a female, and the 2 other did not reach full development.
The preliminary investigations of the fossils were made in situ, but further research is necessary, artdaily reports.
What is known until now, is that these are the only specimens of their type found until now in this region of the country, and they add to the few Prehistorical animals discovered in this type of water bodies, which were dry caves before glaciations.
These fossils challenge the biogeography of bears in the Americas, since Arctotherium was previously known to only have lived in South America.
De Anda said that at first the remains were thought to have belonged to jaguars, but archaeozoologist Christopher Gotz from Yucatan Autonomous University carried out the morphological identification of the skulls, and confirmed they belonged to bears, because of their strong, flat and wide molars.
Gotz said that species related to Arctotherium in America are the extinct North American short-faced bears(Arctodus simus and pristinus), the Florida short-faced (Tremarctos floridanus), the Mexico short-faced (Tremarctos mexicanus) and the last survivor that lives in South America, the Andean short-faced bear (tremarctos ornatus).
Besides the bear fossils, the archaeologists also found skeletal remains of five humans, and further dating of these skeletons should establish if the two discoveries are connected.
De Anda said that “this research is only beginning, and it will most likely provide important data for the knowledge of the first species that inhabited the region, as well as of the historical periods to which human remains yet to be analyzed belong.
“We are looking forward to confirm after analyses that the remains correspond to that genus, since it would enlarge the knowledge regarding this animal’s natural history and their relation with their closer relatives.â€
He announced the details of the discovery at the International Congress American Cultures and their Environment: Perspectives from Zoo Archaeology, Paleo Botanic and Ethno Biology, organized by the Yucatan Autonomous University in Merida, Yucatan.
news.softpedia.com/news/Fossils-of-Extinct-Bear-Found-in-Mexico-165122.shtml
Mexico fossil(s) discovery (Arctotherium)
Christine Dell'Amore
National Geographic News
Published February 3, 2011
There's a new titleholder for the biggest, baddest bear ever found.
A prehistoric South American giant short-faced bear tipped the scales at up to 3,500 pounds (1,600 kilograms) and towered at least 11 feet (3.4 meters) standing up, according to a new study.
Paleontologist Leopoldo Soibelzon holds an upper arm bone of the giant bear next to an elephant's.
The previous heavyweight was a North American giant short-faced bear—a related extinct species—that weighed up to 2,500 pounds (1,134 kilograms). The largest bear on record in modern times was a 2,200-pound (998-kilogram) polar bear shot in Alaska in the 19th century.
The South American giant short-faced bear roamed its namesake continent about 500,000 to 2 million years ago and would have been the largest and most powerful meat-eater on land at the time, scientists say.
(Related: "Ancient Bear DNA Mapped—A First for Extinct Species.")
As meat-eaters go, "there's nothing else that even comes close" during the time period, said study co-author Blaine Schubert, a paleontologist at East Tennessee State University in Johnson City, Tennessee.
"It just blew my mind how big it was."
The bear skeleton, found in Buenos Aires Province, Argentina, in 1935, was recently reexamined by Schubert and study co-author Leopoldo Soibelzon, a paleontologist from Argentina who specializes in South American fossil bears.
By measuring its almost elephant-size humerus, or upper arm bone, the team was able to calculate the size of the rest of the bear's body, Schubert said.
Their analysis also revealed that the animal was an old male that had endured several serious injuries throughout his life.
For Bear, Size Matters
Less certain, however, is what and how these bears ate—and why they were so different from their North American cousins, Schubert noted.
For instance, the South American giant short-faced bear species started huge and became smaller over time, while the North American species grew bigger.
In South America, Schubert suspects, a glut in prey and a lack of competition combined to make the bear king of the continent. But as more meat-eaters evolved, short-faced bears adapted, becoming smaller and more omnivorous, like the modern-day black bear.
(See "Comet 'Shower' Killed Ice Age Mammals?")
In North America, the short-faced bear's increasing size may have offered an advantage—its sheer heft may have scared off saber-toothed cats and other predators from their kills, the researchers speculate.
And the short-faced bear's reign in North America would have also coincided with an explosion in Ice Age megafauna, such as giant ground sloths, camels, and mammoths—all potential new food sources.
"We had an Africa here," Schubert said, and "it's gone now."
The biggest-bear study appeared in the January issue of the Journal of Paleontology.
news.nationalgeographic.com/news/2011/02/110203-biggest-bear-largest-giant-short-faced-animals-science/
Discovery of the Biggest Bear
Bear Hunting Altered Genetics More Than Ice Age Isolation
But the brown bear was not limited to these regions -- Âit could roam freely across major parts of southern and central Europe. The current study analyzed mitochondria from bear remains. Some of the fossils are 20,000 years old. The analysis shows that the genetic pattern in these ancient brown bears differed from that of bears living today.
“Previously today’s genetic structure was interpreted as showing that the brown bear was isolated in southern Europe, just like many other species. But our study shows that this was not the case,†says Love Dalén, one of the Swedes participating in the study.
The new findings show instead that the brown bear survived in central Europe, even during the coldest period of the Ice Age. The scientists now believe that the genetic pattern found in today’s brown bears is the result of historical hunting and of human activities in the brown bear’s natural environment. A few thousand years ago, there were brown bears all over Europe, while today there are just a few remaining populations in Spain, Italy, the Balkans, and Scandinavia.
www.sciencedaily.com/releases/2007/11/071126115307.htm
November 6th, 2010, 11:04 GMT| By Smaranda Biliuti
Four complete skulls and jaws of a Pleistocene bear species called Arctotherium, that disappeared 11,300 years ago, were found by aquatic archaeologists in a submerged cave on the Yucatan peninsula in Mexico.
The 25-30 cm long skulls discovered at 42 meters underwater, belong to two adult bears - one of each sex - and two bears that had not reached full maturity.
The discovery was made by Guillermo de Anda Alanis and his team from the Yucatan Autonomous University, while they were diving in a cavern, as part of the project authorized by the National Institute of Anthropology and History (INAH) “El Culto al Cenote en el Centro de Yucatan†(Cult to Cenote in Central Yucatan).
Guillermo de Anda Alanis said that the fossils were found between the towns of Sotuta and Homun, in Yucatan, spread on a 120 meters diameter surface.
The four skulls seem to belong to a family of bears of the same species, because the 2 adult skulls belonged to a male and a female, and the 2 other did not reach full development.
The preliminary investigations of the fossils were made in situ, but further research is necessary, artdaily reports.
What is known until now, is that these are the only specimens of their type found until now in this region of the country, and they add to the few Prehistorical animals discovered in this type of water bodies, which were dry caves before glaciations.
These fossils challenge the biogeography of bears in the Americas, since Arctotherium was previously known to only have lived in South America.
De Anda said that at first the remains were thought to have belonged to jaguars, but archaeozoologist Christopher Gotz from Yucatan Autonomous University carried out the morphological identification of the skulls, and confirmed they belonged to bears, because of their strong, flat and wide molars.
Gotz said that species related to Arctotherium in America are the extinct North American short-faced bears(Arctodus simus and pristinus), the Florida short-faced (Tremarctos floridanus), the Mexico short-faced (Tremarctos mexicanus) and the last survivor that lives in South America, the Andean short-faced bear (tremarctos ornatus).
Besides the bear fossils, the archaeologists also found skeletal remains of five humans, and further dating of these skeletons should establish if the two discoveries are connected.
De Anda said that “this research is only beginning, and it will most likely provide important data for the knowledge of the first species that inhabited the region, as well as of the historical periods to which human remains yet to be analyzed belong.
“We are looking forward to confirm after analyses that the remains correspond to that genus, since it would enlarge the knowledge regarding this animal’s natural history and their relation with their closer relatives.â€
He announced the details of the discovery at the International Congress American Cultures and their Environment: Perspectives from Zoo Archaeology, Paleo Botanic and Ethno Biology, organized by the Yucatan Autonomous University in Merida, Yucatan.
news.softpedia.com/news/Fossils-of-Extinct-Bear-Found-in-Mexico-165122.shtml
Mexico fossil(s) discovery (Arctotherium)
Biggest Bear Ever Found—"It Blew My Mind," Expert Says
Christine Dell'Amore
National Geographic News
Published February 3, 2011
There's a new titleholder for the biggest, baddest bear ever found.
A prehistoric South American giant short-faced bear tipped the scales at up to 3,500 pounds (1,600 kilograms) and towered at least 11 feet (3.4 meters) standing up, according to a new study.
Paleontologist Leopoldo Soibelzon holds an upper arm bone of the giant bear next to an elephant's.
The previous heavyweight was a North American giant short-faced bear—a related extinct species—that weighed up to 2,500 pounds (1,134 kilograms). The largest bear on record in modern times was a 2,200-pound (998-kilogram) polar bear shot in Alaska in the 19th century.
The South American giant short-faced bear roamed its namesake continent about 500,000 to 2 million years ago and would have been the largest and most powerful meat-eater on land at the time, scientists say.
(Related: "Ancient Bear DNA Mapped—A First for Extinct Species.")
As meat-eaters go, "there's nothing else that even comes close" during the time period, said study co-author Blaine Schubert, a paleontologist at East Tennessee State University in Johnson City, Tennessee.
"It just blew my mind how big it was."
The bear skeleton, found in Buenos Aires Province, Argentina, in 1935, was recently reexamined by Schubert and study co-author Leopoldo Soibelzon, a paleontologist from Argentina who specializes in South American fossil bears.
By measuring its almost elephant-size humerus, or upper arm bone, the team was able to calculate the size of the rest of the bear's body, Schubert said.
Their analysis also revealed that the animal was an old male that had endured several serious injuries throughout his life.
For Bear, Size Matters
Less certain, however, is what and how these bears ate—and why they were so different from their North American cousins, Schubert noted.
For instance, the South American giant short-faced bear species started huge and became smaller over time, while the North American species grew bigger.
In South America, Schubert suspects, a glut in prey and a lack of competition combined to make the bear king of the continent. But as more meat-eaters evolved, short-faced bears adapted, becoming smaller and more omnivorous, like the modern-day black bear.
(See "Comet 'Shower' Killed Ice Age Mammals?")
In North America, the short-faced bear's increasing size may have offered an advantage—its sheer heft may have scared off saber-toothed cats and other predators from their kills, the researchers speculate.
And the short-faced bear's reign in North America would have also coincided with an explosion in Ice Age megafauna, such as giant ground sloths, camels, and mammoths—all potential new food sources.
"We had an Africa here," Schubert said, and "it's gone now."
The biggest-bear study appeared in the January issue of the Journal of Paleontology.
news.nationalgeographic.com/news/2011/02/110203-biggest-bear-largest-giant-short-faced-animals-science/
Discovery of the Biggest Bear