The Deadliest Tooth

6 minutes

(male narrator) This is a story about a deadly tooth and a paleontologist named Jack Tseng. I like to study animals that look weird or awesome.

(narrator) Few animals look as weird and awesome as the saber-toothed cat, Smilodon fatalis. Their mouth are weapons, and that's part of the draw. What were these animals doing? They're so weird looking.

(narrator) Imagine you're in Los Angeles 30,000 years ago.

(Tseng) A Smilodon might look like a mountain lion on steroids. The teeth would not be hidden under the fur. It would be showing. It's pretty scary looking. If you're close enough to see those features,

you probably are... [growling]

are dead.

(narrator) These teeth aren't to be trifled with. Some could grow nearly a foot long. Oftentimes they are serrated, just like steak knives.

(narrator) The saber has evolved six times in different lineages.

(Tseng) Evidence for that tool being a great weapon for carnivores. But just how the saber-tooth used its weapons, well, that's a matter of hot debate. Some people have suggested... They could not hunt because they looked awkward.

(narrator) Jack says that is not true.

(Tseng) If you're a scavenger, you won't need such an extreme tool. Others think they didn't use them to hunt, they just looked sexy with them.

[growl] [wolf whistle]

(narrator) But most agree that these mouth daggers had but one purpose: killing tools, stabbing tools, or cutting tools.


(Tseng) You make this surgical cut on the neck, hopefully, severing either a major artery or the windpipe. Then they can use the back cutting teeth to shear off pieces of the prey.

(narrator) Your blood is running cold from terror and revulsion. Pretty much, yeah. I don't know about others, but I reenact sometimes with different skulls when nobody's looking.


So the cat would prowl very low and slowly, stealthily into the prey. And at the last moment, it would probably just hop. Then use its powerful neck musculature to drive the canines into the throat.

(narrator) Many mysteries remain about these animals. The one Jack and his colleagues wanted to solve was, how long did it take these sabers to grow? They looked at fossils from the La Brea Tar Pits in Los Angeles. They employed a combination of technologies: CT scans--

(Tseng) CT uses x-ray to blast through these fossils or bones.

(narrator) They created 3D images of the teeth and looked at the chemical composition. This tells them about the tooth growth rate. Teeth absorb nutrients as they grow. There's some natural fluctuation in the composition of elements over a year, that you could see a seasonal cycle.

(narrator) They found Smilodon sabers grew about six millimeters per month.

(Tseng) That doesn't sound like much, but in context, human fingernails grow at about 3.4 millimeters per month.

(narrator) Lions, their canines grow half as fast. But it still takes Smilodon longer than most modern big cats to finish growing their extra-long teeth. To grow a seven-inch saber, it will take three years.

(narrator) This tells us a little about the life of baby saber-tooths.

(Tseng) Since it took longer to grow these weapons, it would benefit the cubs to follow their parents for a longer period of time.

(narrator) This is the wonder of modern paleontology. You can start to understand and even imagine the life of the baby saber-tooth cub, an animal that went extinct 10,000 years ago, just by studying some ancient teeth yanked out of a tar pit in L.A.

Funding to purchase and make this educational production accessible was provided by the U.S. Department of Education:

PH: 1-800-USA-LEARN (V) or WEB:

Now Playing As: Captioned (English) (change)

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New research reveals why the saber-tooth tiger needed such large teeth.

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