Despite its fearsome fangs, the saber-toothed cat Smilodon fatalis may have been a relatively wimpy biter—at least compared to modern-day lions.
Computer images like the one above show the pressure exerted by a saber-toothed cat’s jaws. Researchers examining such models can tell the maximum amount of force the cat could create when it bit down on its prey.
An analysis of the images reveals that the fearsome predator could exert just a third of the bite strength of a modern-day lion.
The prehistoric cat with the 6.5-inch (17-centimeter) chompers roamed the Americas as recently as 10,000 years ago, preying on bison, horse, and possibly even woolly mammoths.
Now computer modeling has revealed that the cat’s jaws could apply only about 220 pounds (100 kilograms) of pressure, said Colin McHenry, a doctoral student at the University of Newcastle in Australia.
That’s just a third of the bite strength of a lion, which can exert up to 660 pounds (300 kilograms) of force with its jaws.
The find offers new clues to understanding the hunting style of the ancient predator.
Lions, for example, can bring down their prey by leaping on them and biting their necks.
“But that would put an enormous amount of stress on the [saber-tooth’s] skull,” McHenry said. “So we think it had to tackle its prey before biting.”
Based on the Ice Age cat’s body shape, this isn’t actually surprising, he added.
“People think of [the saber-toothed cat] as a lion with big teeth. But if you’d actually seen it, you’d have thought it was a bear with big teeth. [It was] built for wrestling large prey to the ground.”
McHenry and colleagues at the University of Newcastle and the University of New South Wales publish their findings this week in the Proceedings of the National Academy of Sciences.
Saber-Tooth Crash Test
McHenry’s team used a method called finite element analysis to simulate the stresses that would have been placed on the saber-toothed cat’s skull while biting its prey.
Finite element analysis is a modeling technique developed by engineers for evaluating stresses on mechanical objects such as airplanes.
“You can think of it as a way of digital crash testing,” McHenry said.
The test showed just how much pressure the saber-tooth’s jaws could create before breaking the skull.
The computer model also helped reveal what the cat might have done once it had its prey down on the ground.
Paleontologists have long wondered whether the saber-toothed cat used its signature teeth to attack an animal’s belly or neck.
One argument was that the cats used their fangs to eviscerate their prey, tearing into an animal’s soft underside.
But attempting to hold a still-living buffalo down while biting its belly would allow the prey to thrash around enough to put dangerous pressure on the saber-tooth’s jaw.
Cowboys, however, have long known that they can hold animals like buffalo down by their heads with relative ease.
And this, McHenry said, was probably what the saber-tooth did—using its long fangs to bite its prey’s neck.
Modern lions actually hold prey down in a similar way. But once its prey is secure, the lion kills it with strong jaws designed to crush and suffocate.
With its weaker jaws, the saber-toothed cat couldn’t suffocate its prey. Instead its long teeth would have pierced the animal’s windpipe and carotid artery—killing it fairly quickly.
This might have actually been an advantage for the saber-tooth, since it can take a lion up to ten minutes to kill a buffalo by strangulation.
“That’s a lot of time,” McHenry said, noting that the saber-tooth had to compete with other big Ice Age predators hoping to steal its kill.
“The advantage of a quick kill seems to be quite significant.”
Other scientists agree that computer modeling provides a good way of testing hypotheses about the behavior of extinct animals.
“It’s important,” said Mark Goodwin, a vertebrate paleontologist and assistant director of the University of California Museum of Paleontology.
Similar studies have been done with dinosaurs, he noted, such as one study that examined the cranial strength—and thus the feeding habits—of the Tyrannosaurus rex.
Source from National Geographic
2 responses so far ↓
Ben Schainker // Feb 19, 2008 at 1:20 am
*Sigh* It is time we stopped looking at all the different kinds of convergent saber-toothed evolution as a highly specialized method of delivering a coup-de-grace and started considering the far more likely scenario: All the different species of saber-toothed predators were, most likely, highly evolved highly efficient can-openers.
And they needed to be. The herbivorous megafauna of their day where thick skinned Goliaths. With horns, trunks, teeth, and claws of their own. The predators of the day needed a technique that would work on a variety of prey as diverse as Camels and Mastodons. Rhinos to Giant Sloths.
The over specialized killing techniques theorized today simply wouldn’t cut it. Wrestling their prey to the ground using only claws. Then utilizing their teeth only for a killing neck bite, is highly unlikely for any size of Mastodon. First that they could somehow wrestle one off its feet using only claws. Second that even when a saber-toothed cat opened its mouth 120° it still would have only a few inches of clearance. Much too small to encompass even the smallest of Mastodon necks.
No, everything about the design of saber-toothed mammals tells us how they hunted.
Let us start at their tails and move head-wards:
1) All saber-toothed mammals had reduced or residual tails.
2) Similarly they all had rear legs shorter than their front legs. Legs with powerful muscles that not only propelled them forward, but also allowed them pull their feet up and tuck them under their bodies.
3) Over-developed strong forelimbs with long claws that could grasp and hold onto prey.
4) Very strong neck muscles and attachments.
5) Relatively weak bite strength, as the lower jaw was reduced to make way for the huge sabers. Lower jaws that had to open wider than most mammals just to provide a few inches of clearance. Yet this increased range of motion came at the expense of strength.
6) And the Sabers themselves. Incredibly long and sharp but too delicate to take on hard tissues.
Everyone agrees that these saber toothed predators went after prey much lager than themselves. It is a matter of debate whether they were social and hunted in packs. This author tends to think they did. Few predators evolve to to kill things much larger than themselves, yet couldn’t hope to finish eating on their own.
So how did they do it?
Well here is the thing. Most theories try to explain how sabertooths get both their fangs into their prey at the same time. What if they tried to get only one in? Why only one? That is how Lions hunt Buffalo. Buffalo are about the biggest prey that lions regularly go after. However, Buffalo’s thick skins and giant bulk make it a long drawn out fight. And the African Buffalo have nothing on the size and thick skins of ice age megafauna.
So how do Lions go after Buffalo?
They attack from behind. They leap on the haunches and sides of the buffalo, avoiding the horns and head. They use their front limbs to dig in and hold on. Their back legs either hop along the ground or get tucked up so the sharp hooves don’t trample them. The Lions turn their heads to one side and sink ONE canine tooth into the thick skin and try to hold on. The Lions cooperate. Many Lions cling to the buffalo till it is exhausted and falls to the ground. Then one Lion chomps down on the buffalo’s nose and tries to suffocate it; a move that would be impossible for a saber toothed predator.
Buffalo are at the limit of Lions abilities. And though lions can take down weak elephants and giraffe, and hippos, they are not considered staple prey animals for them. Lions teeth, as big as they are, just aren’t designed to penetrate the thick skins megafauna have developed for defense over the eons.
But during the time when megafauna were evolving those thick skins, several unrelated predators evolved teeth to deal with it: An ancient arms race.
So, what would it look like if a Saber Toothed predator attacked a buffalo?
Like a lion it would jump on the haunches or sides of a buffalo, avoiding the dangerous horns. Its stronger front limbs and claws would easily grab and hold on. It wouldn’t have to worry about the buffalo stepping on its tail and dislodging him, because the Saber Tooth doesn’t have much of a tail at all. Likewise its short hind limbs could be pulled up with its powerful muscles and held free of dangerous hooves, or thrust against the buffalo in a powerful raking/climbing motion, as many cats are known to do today.
And then it would do the Saber Tooth’s signature Can-Opener move:
Turning its head to one side the Saber Tooth would place ONE tooth against the buffalo’s thick skin. It would open its mouth slightly, using its lower jaw mainly as guide to minimize the shearing forces on the tooth. Many Saber Toothed predators actually developed boney “sheaths” on their lower jaws for just this purpose. Then the Saber Tooth would use its massive neck muscles and its own body weight to drive its ONE tooth under the skin of the Buffalo. This thrust would be mostly parallel to the skin, and was NOT directed into the body or boney structure of the Buffalo.
Now what?
Well depending on the prey, there are many options. At this point the Saber Tooth has delivered a deep puncture wound that will probably become septic and eventually kill the animal. If the prey is slow enough to follow on foot and the Saber Tooth isn’t starving, it could probably let go and follow the animal till it died, like a Komodo Dragon.
Or alternatively, if Saber Tooths hunted in packs, they could hang on by TOOTH and claws until the prey succumbs and falls to the ground. But this ONE TOOTH attack gives them another option. As the Tooth sinks beneath the skin another weapon of the Saber Toothed Can-Opener becomes available. When the Tooth is fully sheathed in the prey animal the Saber Tooth can bring its sharp Carnassial teeth into play. This is especially true of Saber Tooth Cats. These are molars that have evolved to work like scissors and are the trademark of the carnivore familiy. Designed for slicing through meat and even bone, with a chewing motion the Saber Tooth could open up huge gaping wounds very quickly and efficiently. Like a Can-Opener in truth.
As for the killing blow, this author is not sure it would be necessary. But if it was, he agrees with others who suggest Saber Tooth predators disemboweled their prey. Others have suggested that this would put them at risk of flailing hooves, but this is not so. If the Saber Tooth climbs onto the downed prey from behind (Saber Tooth’s hind legs on the ground behind the prey’s spine, front legs and head on the prey’s belly) then it would be away from flailing limbs. Using the ONE TOOTH can opener maneuver it could quickly plunge a tooth up into a herbivores huge abdominal cavity and eviscerate it. Not pretty, but it would work on a huge variety of prey available to the Saber Tooths at the time.
So why did Saber Tooths go away? Because the majority megafauna disappeared. Replaced by the faster, smaller ruminants. The primary prey of todays big cats.
-Ben Schainker
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