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The Deadliest Tooth

6 minutes

(Describer) Shown in cardboard and paper figures, a large cat with a pair of long teeth bites down on the neck of a horse creature, drawing blood which spreads.

(male narrator) This is a story about a deadly tooth

(Describer) The Deadliest Tooth.

and a paleontologist named Jack Tseng.

(Describer) He moves the cat figure with a stick and a wire.

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,

(Describer) He holds a skull with two long teeth.

and that's part of the draw. What were these animals doing? They're so weird looking.

(Describer) Clouds have orange edges from low sun.

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

(Describer) Animals stand in long grass.

(Describer) Tsang:

(Tseng) A Smilodon might look like a mountain lion on steroids. The teeth would not be hidden under the fur. It would be showing.

(Describer) It's dark yellow with dark grey spots.

It's pretty scary looking. If you're close enough to see those features,

you probably are... [growling]

(Describer) The cat's mouth is open.

are dead.

(Describer) Mechanics of the Mouth-Sword.

(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.

(Describer) Its open mouth holds a red rose.

[growl] [wolf whistle]

(narrator) But most agree that these mouth daggers had but one purpose:

(Describer) It stalks three horses.

killing tools, stabbing tools, or cutting tools.

(Describer) It bites down on a smaller animal.


(Tseng) You make this surgical cut on the neck, hopefully, severing either a major artery or the windpipe.

(Describer) Red comes out of a horse's neck.

Then they can use the back cutting teeth to shear off pieces of the prey.

(Describer) An open carcass is made of paper.

(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.


(Describer) On a white background, title: Mammal Theater. “Mammal” is in all capital letters, and “theater” is in all lower-case. Tsang holds a cat's skull as he stalks down a hall.

So the cat would prowl very low and slowly, stealthily into the prey.

(Describer) He stalks toward a skeleton of prey.

And at the last moment, it would probably just hop.

(Describer) He moves the skull onto the neck bones of the prey, whose skull is lowered as if grazing.

Then use its powerful neck musculature to drive the canines into the throat.

(Describer) He angles the teeth around the neck.

(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?

(Describer) How Do Your Weapons 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.

(Describer) A cat sits in the grass.

(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,

(Describer) Two of them play.

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

(Describer) Shown with pictures of mannequins of big cats in museum dioramas, titles: This project was made possible by the Alfred P. Sloan Foundation. Directed and produced by Flora Lichtman and Sharon Shattuck. Written and edited by Flora Lichtman. Narrated by Dave Pettitt. Copyright 2015 Sweet Fern Productions. Funding to purchase and make this educational program accessible was provided by the U.S. Department of Education. Contact the Department of Education by telephone at 1-800-USA-LEARN, or online at

accessible was provided by the U.S. Department of Education:

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

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Media Details

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