This Ancient Bear Towered Over Polar Bears and Was One of the Largest Ever

3D illustration of Arctodus in a snowy forest
© Warpaint/

Written by Krishna Maxwell

Updated: October 6, 2022

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The Arctodus (Ark-toe-dus), or short-faced bear, was one of the largest bear genera that ever walked the earth. It existed during the Pleistocene epoch from 1.8 million years ago to 11,000 years ago. It was most abundant in California and some parts of the central United States. There are two common species of Arctodus: the Arctodus pristinus and the Arctodus simus. The latter is known to be one of the largest terrestrial mammalian carnivores.

This bear was characterized by its short face and broad muzzle. This is why it is also commonly referred to as “bulldog bear.” It stood five feet at the shoulders when walking and 12 feet when standing on its hind legs. Despite being about 1500 pounds, the Arctodus can run fast at up to 40 miles per hour.

Named byJoseph Leidy in 1854
ClassificationsChordata, Mammalia, Carnivora, Ursidae, Tremarctinae, Tremarctini
DietCarnivore / Adaptable omnivore
Size5 feet when on all fours, 12 feet when standing on hind legs
WeightAbout 1500 pounds
Known locationsThroughout North America
HabitatOpen grasslands for A. simus and woodlands for A. pristinus
Time periodPleistocene
3D rendering of Arctodus on a white background
Arctodus or Short-faced Bear is an extinct mammal that lived in North America in the Pleistocene Age.


Description and Size

The name Arctodus is not very well known since it is called by the name “short-faced bear.” In fact, Arctotherium is more popular in South America since it has a more robust build than the Arctodus, though the latter was larger in terms of skeleton size. Despite its size, it was the fastest running bear that ever lived. It had longer legs than bears of today as it could stand up to 12 feet on its hind legs.

The Arctodus’ toes pointed straight forward, unlike the pigeon toes of modern bears. This enabled them to walk and run faster. They had a purposeful gait that made them more intimidating in their habitats. The Arctodus could run up to 40 miles per hour despite weighing over 1500 pounds.

An average male polar bear’s weight is only about 1300 pounds. A brown bear’s weight is usually less than a polar bear’s.


Based on fossils, the Arctodus had a domed skull, broad snout, and short back. Some studies said that the term short-faced bear could be misleading because the Arctodus’ should not be considered short-faced for a bear its size.

According to research, its cheek teeth were tall and well-developed, while its canine teeth were massive but shorter than those of other bears. When fossils of its teeth were found, experts didn’t see signs typical of a carnivore. This led them to believe that the Arctodus could be an omnivore.

The Arctodus was flat-footed since their feet were plantigrade. They also had a “false thumb” due to their wrist’s enlarged radial sesamoid. Today, this thumb can be seen in the giant panda and the spectacled bear.

What Did Arctodus Eat?

Paleobiologists believed that the short-faced bear was a true carnivore. They ate only meat. This is based on the presence of a very high ratio of nitrogen-15 to nitrogen-14 in their bone samples. However, other experts explained that the Arctodus could also be omnivores, which means they also ate plants.

The skull and shearing type of teeth of the Arctodus meant it was more of a carnivore than a plant-eater. It also had the ability to crush bones to obtain the bone marrow, as evident in the width of its jaws.


The Arctodus lived in grasslands and woodlands. In particular, researchers believed they were in the eastern and possibly central United States. They could’ve inhabited Maryland, coastal South Carolina, Florida, Kansas, and southeastern Pennsylvania. They could also be found in Mexico, and some believed Arctodus also existed in modern-day Canada.

The short-faced bear also lived in Alaska and Yukon and in Minnesota, and west of the Mississippi River. Experts believed the Arctodus preyed on large herbivores, such as horses, bison, deer, ground sloths, caribou, and muskoxen.

It is primarily believed that the Arctodus also inhabited some parts of Canada. Specimens were found and recorded in the Pellucidar Cave in Vancouver Island in British Columbia, Edmonton in Alberta, and Lebret in Saskatchewan.

The enormous short-faced bear, or A. simus, lived in the high grasslands of western North America. This is the species that experts said was solitary. The smaller and lighter A. pristinus inhabited the wooded coastal region in the Atlantic.

Threats and Predators

The Arctodus was more of a solitary hunter or scavenger. It did not hunt in packs or groups. At first look, because of its size and power, the short-faced bear looked like an apex predator. However, science has disproved this, and the more logical discovery is that the Arctodus was both a predator and scavenger.

Due to the isotopes found in the animal’s tissues, the analysis for Arctodus showed that it was a hypercarnivore. This term refers to animals whose 70% to 100% of tissues came from other animals. The study also revealed that the short-faced bear ate all kinds of animals. It wasn’t particular to any animal like the Smilodon to a bison. This meant that the Arctodus was not entirely a predator. Instead, it was more of a scavenger.

The long limbs of the short-faced bear gave it an advantage over its prey. Using its limbs, the Arctodus could swipe at its target. It would have been easy, too, since the bear had long legs and broad strides that rivaled most prey.

It is hard to imagine any other animal threatening the Arctodus during its time. It was one of the largest carnivorous animals since dinosaurs disappeared after the Cretaceous period. No other animal would dare pose a threat to the short-faced bear.

A saber-toothed cat tries to drive a short-faced bear out of its territory.
Arctodus bears’ teeth were two inches long and their claws were 3 inches long, so they probably didn’t have to fear saber-toothed cats.

©Daniel Eskridge/

Arctodus Discoveries and Fossils

The Arctodus was first discovered in 1854. Its fossil remains were found all over North America, though some 150 materials were in Florida. The largest known skull of the short-faced bear was discovered by a gold miner at Gold Run Creek in Yukon, while a skull from a female Arctodus was in Ophir Creek.

The Ophir skull was the “finest” one to date since studies found that this particular female Arctodus survived until the cold peak of the last glaciation in Eastern Beringia, or parts of Alaska, Northwest Territories, and Yukon.

Many fossils were dug up in Florida. Particularly, the Arctodus pristinus were found in Alachua County, Brevard County, Charlotte County, Citrus County, Columbia County, Apollo Beach in Hillsborough County, McLeod Limerock Mine in Levy County, Okeechobee County, Sarasota County, and Sumter County.

Experts categorize the fossils for Arctodus into two: the smaller ones were for the A. pristinus, while the more gigantic ones were for the A. simus. For example, the premolars and molars of the pristinus were smaller than those of the simus.

The size of the fossil samples also differs, depending on the gender of the short-faced bear. Female Arctodus was smaller and had lighter builds, while males were more massive.


To understand why the Arctodus went extinct, remember one thing: that this short-faced bear was a specialized scavenger. It would have been reliant on larger mammal prey and the predators that could overtake them. However, at the end of the Pleistocene age in North America, powerful predators, such as the dire wolves, Smilodon, and the American Lion, went extinct. This meant for the Arctodus that there were no more large predators to catch prey and leave remains for them to scavenge.

Like most of the giant animals that roamed the earth at the time, the change in the environment, particularly the climate, would have pushed the Arctodus to extinction too. While most animals have survived different epochs and glaciations, these massive creatures were highly specialized to survive in a specific environment. Because of their size and the dietary needs required to support such size, they would have faced added pressure to adapt more quickly than smaller animals who had lower calorie needs and faster reproduction rates. Given the challenges, it was only a matter of time before their age and skills could no longer fit into the new environment.

Similar Animals to Arctodus

The Arctodus is compared to existing bears today:

  • Black bears: There are many black bears, including American, Asian, Californian, Eastern, Mexican, and Louisiana. The American black bear is the most common and is usually found in forests in North America. These are large and stocky with short tails. They can grow up to six feet in length and up to 600 pounds.
  • Brown / Grizzly bears: This type of bear can grow as tall as eight feet and as heavy as 800 pounds. Grizzly bears are brown bears, only that they are found in North America. They got their name from their fur, which appears grizzly. Conservation laws protect the existence of grizzly bears because hunting and urbanization threaten their survival.
  • Polar bears: This is the largest bear in the world. Polar bears are also the Arctic’s top predators. Male polar bears can weigh as much as 1300 pounds, while females are up to 700 pounds. They are found in the Arctic Ocean, sea ice, and nearby coastal areas.

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About the Author

Krishna is a lifelong animal owner and advocate. She owns and operates a small farm in upstate New York which she shares with three dogs, four donkeys, one mule, and a cat. She holds a Bachelors in Agricultural Technology and has extensive experience in animal health and welfare. When not working with her own animals and tending her farm, Krishna is helping other animal owners with behavior or management issues and teaching neighboring farmers about Regenerative Agriculture practices.

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