| Giant Short Faced Bear Fossil range: Middle to Late Pleistocene |
|
|---|---|
 |
|
| Restoration of Arctodus simus | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Carnivora |
| Family: | Ursidae |
| Subfamily: | Ursinae |
| Tribe: | Tremarctini |
| Genus: | †Arctodus |
| Species: | †A. simus |
| Binomial name | |
| Arctodus simus (Cope, 1897) |
|
 |
|
| Range of Arctodus simus | |
Arctodus simus, also known as the giant short-faced bear, is an extinct species of bear. The genus Arctodus is known as the short-faced or bulldog bears. It was native to prehistoric North America from about 800 thousand years ago, and became extinct about 12,500 years ago. It was appeared to be the largest bear in the fossil record (average size overlapping with the largest Polar Bears, Cave Bears and Brown Bears) and among the largest mammalian land predators of all time. The type specimen came from Potter Creek Cave in Shasta County, California. [1] Males from the Yukon region - the largest representatives of the species - would have stood about 1.6 m (5.3 ft) at the shoulder (on all fours), 3.7 m (12 ft) upright and may have weighed about 1135 kg (2500 lb).[2]
Contents |
The short-faced bears belonged to a group of bears known as the tremarctine bears or running bears, which are endemic to North America and Europe. The earliest member of the Tremarctinae was Plionarctos edensis, which lived in Indiana and Tennessee during the Miocene Epoch, (10 mya). This genus is considered ancestral to Arctodus, as well as to the modern spectacled bear, Tremarctos ornatus. Although the early history of Arctodus simus is poorly known, it evidently became widespread in North America by the Kansan age (about 800 kya).
A. simus was endemic to North America, where it ranged from the north central plains of Alaska and Canada to central Mexico, and California to Virginia. It was the most common of early North American bears, being most abundant in California.[3]
Analysis of Arctodus bones showed high concentrations of nitrogen-15, a stable nitrogen isotope accumulated by meat-eaters, with no evidence of ingestion of vegetation. Based upon this evidence A. simus was highly carnivorous, and as an adult would have required 16 kg (35 pounds) of flesh per day to survive.[4][5]
One theory of its predatory habits envisions Arctodus simus as a brutish predator that overwhelmed the large mammals of the Pleistocene with its great physical strength. Some consider this problematic, as Arctodus, though very large, was gracile in build. In order to bring down fellow megafauna, some believe this bear would have had to be a more robust creature, with a denser skeletal structure. Alternatively, the long-legged Arctodus may have run down Pleistocene herbivores such as steppe horses and saiga antelopes in a cheetah-like fashion. However, in this scenario, the bear’s sheer physical mass would be a handicap. Arctodus skeletons do not articulate in a way that would have allowed for quick turns, an ability required of any predator that survives by killing agile prey.[5] Dr. Paul Matheus, paleontologist at the University of Alaska Fairbanks, determined that Arctodus' moved in a pacing motion like a camel, horse, and modern bears, making it built more for endurance than for great speed.[5] Arctodus simus, according to these arguments, was ill-equipped to be an active predator, leading some to conclude that it was a kleptoparasite[5], using its enormous size to intimidate smaller predators such as dire wolves, Smilodon and American lions from their kills.
Though seen by some as primarily a scavenger, its 30-45 mph speed and fearsome natural weapons could have allowed it to attack fast moving prey like horses and slow-moving animals such as ground sloths, according to U.S. National Park Service paleontologist Greg McDonald.
Recently closer dietary research on the giant short-faced bear as well as the Cave Bear suggests that both bears were omnivores like modern bears, and that the former did eat plants depending on availability.[6]
The giant short-faced bear became extinct some 12 millennia ago, perhaps partly because some of its large prey died out earlier, and partly also because of competition with the smaller, more omnivorous brown bears that entered North America from Eurasia. Since its demise coincides with the development of the Clovis technology and improved hunting techniques by humans in North America, hunting pressure may also have contributed to its extinction, both directly (human hunting) or indirectly (due to the depletion of other large mammals which it may have followed to scavenge kills or depended upon as prey).
In the BBC series Wild New World a giant short-faced bear is seen approaching a pack of lions eating a dead prey. The bear tries to scare the lions away, but to no avail. In another BBC series; Monsters We Met, in an episode depicting the Ice Age in North-America, a man is walking close to a herd of mammoth. Suddenly, he spots a short faced-bear, lurking on the other side of the mammoth herd. The bears spots the man, and starts chasing him. The man gets caught up by the bear in a small grove. He screams as the bear lifts its paw and strikes him. The man dies instantly, and is presumably eaten by the bear.
Arctodus appears in Jurassic Fight Club where it fights an American Lion for a bison carcass.
|
|
Wikis
Search
