Boneblogger: Science and the outdoors

Exploring the natural world

How big was the Giant Short-faced Bear?

The character of living things on land changed forever after the Cretaceous-Tertiary extinctions, 65 million years ago. The dinosaurs on land and the marine reptiles in the oceans went extinct, leaving way for mammals and birds to evolve into those niches once held by the “terrible lizards” (dinosaurs) and other giant reptiles.

Throughout the Cenozoic, sometimes “mammal-centrically” referred to as the Age of Mammals, these warm-blooded, fur-covered creatures diversified into a wide range of beasts, including humans. While many of the land mammals got very large, they never matched the recording-holding dinosaurs for superlative size on land.

The largest animals ever known to have lived actually evolved after the dinosaurs and are in fact alive today. An ancient lineage of mammals returned to the oceans and evolved into the modern whales. (See the note about the largest animals feeding upon the smallest).

People are always excited about the Carnivores, or meat-eating mammals. There is something about the dangerous and frightening that excites our primitive nerve centers, so the carnivores are among the most popular at the zoo. (Technical note here—the word carnivore is used in two ways. Carnivore (with a capital “C”) can refer to the class of mammals, the Carnivora, most of whom, but not all, are carnivores (with a lower case “c”), meaning they eat meat. So, not all carnivores are Carnivores, and not all Carnivores are carnivores. Got it? Good.) (Also, see the series on Dangerous Animals for additional exciting facts.)

For example, I recall a visit to the Cincinnati Zoo, and while watching the famed white tigers my young daughter was thrilled when one watched her intently and kept pace with her on the ground while she ran giggling high above on the wooden walkway. She thought that it was a special treat to have one of these magnificent animals take a special interest in her. She felt less special when we mentioned to her that the tiger may not have had cuddling on its mind.

Elsewhere (see related posts below) we have discussed the Giant Short-faced bear (GSFB), Arctodus simus, the great bear from the Ice Age that lived across North America. The GSFB is the largest mammalian Carnivore known, but just how big was it?

Recreation of the Giant Short-faced bear showing its size next to a human

Recreation of the Giant Short-faced bear showing its size next to a human

Many people have examined this question, and one study lays it out clearly (Christiansen 1999). Christiansen examined both the GSFB and its European cousin, the Cave Bear (Ursus spelaeus), another bear famous for its dimensions. Several skeletal measurements have been shown to correlate to overall body mass in mammals. It makes sense that large species have bones of greater relative diameter than small species, and the relationship is more or less linear. By making these measurements a very good estimate of body mass can be made for extinct mammals.

Christiansen used many skeletal measurements of modern carnivores with known body mass to create his linear equations and then plugged in both species of bears to see what the formulas suggested. The results of this study are clear—the GSFB far outweighed any of the modern bears and the cave bear.

These data suggested that a typical (average) GSFB would have weighed in at about 1,700 pounds. Given that there are exceptional individuals, it is estimated that a really large specimen could easily have weighed more than 2,200 pounds. In contrast, the cave bear seems to have a mean body mass of about 1,000 pounds, with exceptional individuals approaching the average for the GSFB.

To further help put this in context, below is a list of select modern and extinct animals and their average body masses. I threw in a couple of dinosaurs for good measure:

Animal

Body Mass (pounds)

Blue Whale

396,830

Brachiosaurus (extinct)

62,300

T. rex (extinct)

14,600

Giant Short-Faced Bear (extinct)

1,700

Kodiak Bear

1,090

North American Lion (extinct)

1,000

Cave Bear (extinct)

1,000

Polar Bear

900

African Lion

375

Indian Tiger

320

American Black Bear

230

Human

160

Leopard

115

Puma

100

Velociraptor (extinct)

98

Cheetah

86

Gray Wolf

78

Wolverine

27

Red Fox

12

No matter how you look at it, “Giant” is a good name for Arctodus!

Christiansen, P. 1999. What size were Arctodus simus and Ursus spelaeus (Carnivora: Ursidae)? Ann. Zool. Fennici 36(93-102).

Related posts:

GSFB, a Northern California Original

Denning behavior in the GSFB

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9 thoughts on “How big was the Giant Short-faced Bear?
  • [...] What is perhaps most striking about this bear is its size. Arctodus is the largest mammalian carnivore ever discovered. It is larger than any of the modern bears, tigers, or lions by a significant degree. An estimate for the largest Arctodus found to date suggests that if the individual was “lean” it weighed from 1,300 to 1,400 pounds (Nelson and Madsen, 1983). In contrast, a male lion weighs about 450 pounds. (See How big was the GSFB?) [...]

  • [...] Posts: GSFB, a North California Original Denning Behavior in the GSFB How Big was the GSFB? Polar Bear [...]

  • adorety says:

    Polar bears have a body mass between 1200 and 1500 pounds and are the largest living land predator. Please check your chart on body mass for predators under the short faced bear entry. Otherwise nice read and info.

    • Greg says:

      @Adorety, thanks for the comment. As you note, polar bears can reach 1,500 pounds. My chart gives a much more modest 390 pounds, and I have wondered if that is ambiguous. The issue is that the chart gives average body mass, and bears in particular show a wide range of sexual dimorphism, that is, the males and females widely vary in size. Male bears reach the mass you mention, but females are much smaller. By including the average for both sexes, the average is perhaps misleadingly low, but I was trying to be consistent with all the species listed.

      • Paul says:

        Sorry Greg, but that’s still not right. There is indeed a large difference in weight between male and female polar bears, but not enough to bring the average down that far. Even females tend to weigh more than 390 pounds. I’d guess you’ve listed the average polar bear weight in kilograms, but the other bears are listed in pounds. Taken in kilograms, the figure 390 makes sense. See here: http://www.loc.gov/rr/scitech/mysteries/bear.html and http://www.seaworld.org/infobooks/polarbears/pbphysical.html

        • Greg says:

          I stand corrected. I do not have notes of where I got the original body mass estimates, and you are right, it looks like I may have mixed up my units. If so, at least I can say NASA did it too :-)

          I have corrected the chart above to make the average mass near 900 pounds. Thanks.

          • ashey says:

            this wabsite is going to get me an A+ on my geography report on the giant short-faced bear. i love this website.

  • ashey says:

    this website is going to get me an a+ on my geography report.i love this website

  • […] This big cat lived mostly across the western half of North America, and ranged into South America as far as Peru. Its remains are plentiful in the tar pits of Rancho La Brea. It is clear that this is a big animal. Estimates of body size suggest a weight of about 1,000 pounds, and that it stood 4 feet at the shoulder. For comparison, the modern African lion weighs in at about 375 pounds. This American cat would have been the second largest mammalian predator, right behind the giant short faced bear. (See How big was the Giant Short-faced bear?) […]

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