Arctodus — known as the short-faced bear or bulldog bear — is an extinct genus of bear consisting of two known fossil species: Arctodus simus and Arctodus pristinus. They were native to North America during the middle to late Pleistocene epoch. It was thought to be carnivorous, though like modern bears, it was probably not above meal of any kind. Its bones were long and thin, and it believed to be able to run up to 50 km/h for short distances. It was large creature, and likely the apex predator of its day and location. Its large size, combined with the natural toughness of bears, meant that it probably preyed upon the North American megafauna.
However, relying on the North American megafauna as its main food source, it disappeared at the same time they did, possibly partly due to competition with humans for the same limited game.
Tremarctos ornatus, the spectacled bear of South America, is the closest living relative of the short-faced bears.
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. A. simus is the largest bear, and more generally, the largest mammalian land carnivore within the last 20,000 years. It was native to prehistoric North America from about 800 thousand years ago, and became extinct about 12,500 years ago. It was the largest terrestrial carnivore of its day. The largest mature males would have stood 1.8m (6 ft) at the shoulder (on all fours), 4m (13 ft) upright and an impressive 900kg (2000 lb).
Arctodus simus are a scavenging or necrophagy, they were using its enormous size to intimidate smaller predators such as dire wolves, Smilodon and American lions from their kills.