Extinct Short-faced Bear

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The Giant Short-faced Bear

Arctodus simus

The Fastest Running Bear That Ever Lived

Also called the bulldog bear, the giant short-faced bear (Arctodus simus) was undoubtedly the fastest running bear that ever lived. Rangier and longer legged than any bear today, it was about five feet at the shoulders when walking and stood as tall as 12 feet on its hind legs. Unlike pigeon-toed modern bears, its toes pointed straight forward, enabling it to walk with a fast, purposeful gait. It probably could run over 40 miles per hour despite weighing over 1500 pounds.

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Bear Evolution

Early bears

Bears are the youngest of the carnivore families, having arisen from doglike ancestors during the Eocene Epoch 55 million to 38 million years ago. The earliest bears had the characteristics of both dogs and bears, with heavy-set features and blunter teeth than those of true dogs.

Modern bears (including Asian black, sun, and sloth bears and extinct bears)

Modern bears appeared in Eurasia around 5 million years ago during the late Miocene Epoch. These bears were relatively small animals, but some types eventually grew quite large. They diversified and spread through Europe, Asia, and North America, eventually reaching South America. Fossils indicate that bears once lived in Africa, with one large primitive species found as far south as present-day South Africa.

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How big was this Short-faced Bear?

arctodus_skeleton.jpgOn 4 feet, he was 5½ to 6 feet at the shoulders.

With the front legs straight, the skeleton is 66 inches to the top of the shoulder blades (the big shield-shaped shoulder bones). If short-faced bears had a hump of muscle on the shoulders, he could have been as much as 6 feet at the shoulders.

On 2 legs, he stood 11 to 12 feet tall.

From the crown to the hip joint and down to the heel is 134 inches. That’s 11 feet, 2 inches standing up looking at you or peering down through a basketball hoop. He could look up and bite a branch 12 feet high.

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Why are black bears so timid?

bear_ready_to_climb_tree.jpg The Pleistocene Ice Age was a dangerous time for black bears across North America.

For hundreds of thousands of years—until about 10,000 years ago—North America was home to saber-toothed cats, American lions, dire wolves, and giant short-faced bears.

Black bears didn’t stand a chance against any of these predators in a fight, but the black bear was the only one of them able to climb trees. Black bears stayed near trees and lived by the rule “Run first, ask questions later.” They develop a mind more like that of a prey animal than a predator.

Today, the black bear’s timid attitude aids survival in the face of grizzly bears, timber wolves, and people.