Friday, February 4, 2011

Prehistoric Bones Found of Largest-Ever Bear

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. ...

via Prehistoric Bones Found of Largest-Ever Bear - Tech Talk - CBS News.


ndemichael said...

This is absolutely ridiculous. It is ridiculous not because it is hard to believe, but that it really is true. The grizzly bear is absolutely paled in comparison to this bear, and a fully-grown grizzly is frighteningly large. My questions is, how in the world did bears get to be so large, and why are they so small today compared to this size of bear? The article states that the record for the largest known bear was 2,200 lbs. this bear had to have weighed at minimum 1300 lbs more, and stood several feet higher than the known record. I realize that the type of bear and time period in which it lived could have an impact on the difference in size and weight (almost two tons!!) compared to the other bears common to North America, but it is still crazy to think that due to microevolution, an animal could get to be this large in comparison to its distant cousins a continent away. Seeing this bear in the wild certainly would have struck fear into any living animal's heart. I am curious about two things, however. First, what would this bear look like in appearance in comparison to, say, a black, brown, polar, or grizzly bear? and my second question is, how long could an animal like this live? Would he live a relatively short life due to his immense size, or would he be capable of living longer than the typical life expectancy of a bear during the time period in which he lived? His size makes me think he lived to be quite old, but that may be deceiving.

Sam said...

ndemichael, giant mammals were actually the norm for a while. Recall the Mammoth, which was not simply a hairy elephant, but also enormous compared to modern elephants. Do a Google search for "giant extinct mammals" for a plethora of examples.

Xeno said...

Would any modern animals like bears grow to be this big if they were transplanted to a planet exactly like ours, but with less gravity?