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(suspenseful music)

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Forget tigers.

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Forget lions, and leopards.

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One ferocious feline killed its prey with canines

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nearly a foot long.

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(tiger growling)

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But while the beast weighed close to half a ton,

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walked on paws three times larger than a Bengal tiger's,

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Smilodon remains one of the most enigmatic predators,

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past or present.

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(tiger growling)

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Now, scientists on different continents

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are breaking in to Smilodon's secret life

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through those incredible fangs.

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So there's lot of advantages of having these

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elongated sabers, one of which is the ability

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to have your prey bleed out very quickly.

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Dr. Larisa DeSantis is a vertebrate

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paleontologist at Vanderbilt University.

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The saber teeth are actually as long, if not longer,

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than some T-Rex teeth.

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Dr. Nicolas Chimento is at the

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Comparative Anatomy Lab of Vertebrate Evolution

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in the Natural History Museum, Buenos Aires.

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(speaking in foreign language)

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This is original material

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from a saber tooth cat, a Smilodon populator.

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It was found here in (foreign language)

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in the Pampas region.

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His new discovery in Argentina

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suggests that knife-tooth used its canines

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not just to dispatch prey, but to battle with members

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of its own kind.

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(Nicolas speaking foreign language)

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The study that we conducted

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was based on two skulls that had a perforation in this area.

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And when we began to analyze the fang,

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and then introduced it into the hole,

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it fit perfectly.

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The damaged skulls weren't found together,

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but both have similar holes at the top of the nasal area,

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between the eyes.

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Nicolas quickly ruled out natural decay and disease

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as possible causes of the wounds.

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His team concluded that the injuries could have

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only been inflicted by another large animal.

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A swift kick from a hoofed mammal would leave

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a very different type of injury.

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Bear or dire wolf fangs would've left

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much smaller punctures.

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(Nicolas speaking foreign language)

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Here it had an oval shaped hole,

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and the shape coincided with the canine

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of a saber tooth cat.

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So what we did was insert the canine into that hole

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and it matched the shape and fit perfectly inside the skull.

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The punctures in both skulls

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could only have been inflicted by other Smilodons.

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So this is a wound that would have

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undoubtedly caused the animal to die.

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The Argentine specimen shows a wound

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that appears to be instantly fatal.

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It's a huge discovery, as Smilodon fossils

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are relatively rare in South America.

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The lethal injuries may be from male cats

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fighting for mates, or defending territory.

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But no one has been able to confirm the sex

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of any Smilodon fossil.

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Unlike many mammals, males and females

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were about the same size.

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They don't display a large degree of sexual dimorphism,

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which is that the males are fundamentally larger

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than the females.

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So it is pretty hard to tell apart males and females

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and really not possible in these extinct saber tooth cats.

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Dr. DeSantis unpacks saber tooth behavior

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by examining minute details on and in their teeth.

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Larissa works on Smilodon fatalis,

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which roamed North America, and chased its prey

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into the sticky La Brea Tar Pits.

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Smilodon was the only creature during the Pleistocene

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with foot long fangs.

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Despite their fierce nature and lethal weaponry,

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her research at La Brea reveals surprising details

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about the importance of saber fangs.

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Smilodon kittens didn't sport true fangs

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until they were about three years old.

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There is a true evolutionary benefit to having that tooth

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come completely in before the other tooth,

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the baby tooth, falls out.

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And that provides evidence that these animals

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were potentially provisioned or cared for

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because those teeth were so critical to their survival.

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The cat's impressive cuspids slowly grew

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while the baby teeth were still present,

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adding protection to the developing fangs.

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And what's really neat is that there's actually

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this sort of little groove on the inside

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of that deciduous tooth where the adult tooth

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will start to actually come in as well.

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The saber teeth would actually grow in

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alongside that baby tooth until it was erupted,

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at which point then they had their adult saber.

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But then, those fangs grew twice as quickly

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as those of modern day lions.

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That's twice as fast as human fingernails,

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about a quarter inch per month.

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Until their weaponry was fully developed, Smilodon kittens

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needed to stick close to mom.

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It was taking a long time for these teeth to develop,

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and those were that critical for hunting,

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then there may have been an extended period

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of parental care, allowing for these animals

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to become more mature and able to hunt effectively

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on the landscape.

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This suggests that the prehistoric cats

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may have had expanded family structures similar to wolves.

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There has to be some level of care

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for the young individuals that's compensating for the fact

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that it's gonna take a long time

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for these sabers to develop.

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We're not sure if saber toothed cats

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hunted in pairs or in prides, but they worked together.

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We think that they were at least hunting

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in some sort of multiple cat scenario

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because of the high abundance of saber tooth cats

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found at La Brea.

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On hot Pleistocene days, only an inch or two

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of sticky tar would've trapped animals forever.

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So if you have leaf matter covering these tar seeps

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or if it looks like it's a watering hole

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and you sort of step in, all it requires is stepping in

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a few inches even to begin to get stuck

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and unable to move yourself out.

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Smilodon preferred to ambush its prey,

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force it into submission, and then bite down.

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(suspenseful music)

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(animals squealing)

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(Nicolas speaking foreign language)

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In general, a saber tooth's back limbs

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were a bit shorter and more robust.

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And the front limbs were a little longer.

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They prefer to hunt using short bursts.

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The saber tooth cats were taking down prey

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from more forced eco-systems, eating things like

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tapirs or maybe some camels or deer.

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The prehistoric landscape was rich

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with forests and prairies, with many big beasts.

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Giant ground sloths, short faced bears,

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mammoths and mastodons, and camel-like creatures

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lived side-by-side with Smilodon.

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Saber toothed cats were the apex predators

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throughout Pleistocene America.

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First appearing two and a half million years ago,

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then vanishing just 8,000 years ago.

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(speaking foreign language)

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There was a large variety of prey,

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and saber tooth cats would choose the largest and heaviest.

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It could consume a young mastodon, so a 1,000,

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1,500 kilo animal might've been hunted by a Smilodon.

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Despite their dental arsenal,

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Larissa's research also reveals insights

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about the complex social lives of saber toothed cats.

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Smilodon fossils from La Brea show injuries, too,

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and something else.

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So specimens that have arthritis or have had an abscess

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to their tooth, or who have had a broken canine,

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for example, these broken sabers, and one of the things

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that's often found is that there's evidence

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that they've healed from these injuries.

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They've lived for some prolonged period of time.

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Not all of the saber toothed cats

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died in the tar.

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Many lived to ripe old ages, despite serious injuries

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from panicked prey or other cats.

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With all of these different injuries,

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we started to wonder, were these animals

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doing something different?

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If you were kicked in the jaw, or you had an abscess,

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were you relegated to the outside of the pack

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or relegated to hunting by yourself?

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Were you desperate, were you chewing on carcasses

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and just sort of eating the scraps of what you could find?

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Larissa DeSantis can tell exactly

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what an extinct creature ate throughout its lifetime.

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(scraping tooth) You are what you eat.

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Everything you eat is incorporated into your tissues

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with a different sort of fractionation factor.

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Whether you eat lots of fish or if you eat lots of meat,

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all of that is incorporated to your hair, your fingernails,

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your bones, your teeth.

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And what's great about teeth is it locks in that signature

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and preserves it over thousands to millions of years.

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So we can actually analyze the teeth of fossil animals

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and get an understanding of what they were eating.

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By analyzing the chemical signature

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of a Smilodon's tooth enamel, she can see what it preyed on

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and where that prey lived.

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And by studying the microscopic grooves and wear

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on the surface of the teeth, she can tell whether the owner

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crunched bone or dined on delicacies.

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And what we actually found was pretty interesting

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is that the individuals that were injured

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were actually eating softer foods, and this suggests

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that potentially they were actually being provisioned food.

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So these weren't animals that were just desperately

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scavenging for whatever food they could find,

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they were actually able to get access to the flesh, likely,

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potentially by other cats.

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And so that was really, really an exciting find.

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I mean that is quite remarkable,

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because that suggests that these animals were really,

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you know, caring for each other.

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So this is the hole where a canine would fit.

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But this shows where it lost its canine

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and the bone grew in, in this area.

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And so this animal lived for some prolonged period of time

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with the loss of its canine.

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This behavior is seen in African lions today.

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Rare footage from Tanzania shows an able-bodied lioness

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ensuring that a senior cat with a broken jaw

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has access to palatable food.

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While the discovery in Argentina reveals that Smilodon

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may have been even more ruthless than previously thought,

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these great saber cats clearly developed strategies

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that ensured their survival.

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Smilodon disappeared frustratingly close to us in time,

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going extinct around the end of the last glacial period

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when humans were relatively new to the Americas.

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Did they meet their match in us?

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(speaking foreign language)

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The majority of herbivores had adapted

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to live in wide open spaces,

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and the giant grasslands of South America.

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As it got hotter, environments like forests and jungles

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developed faster, which means that the number

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of giant herbivores began to decline.

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And, in the last ice age, many were also

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being hunted by humans.

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A combination of these two factors, we're talking about

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climate change that altered eco-systems, plus human beings,

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delivered the fatal blow to many species.

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The other great thing about La Brea is that we're finding

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these fossils from about 50,000 years ago til the present.

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And so they have different ages and different dates.

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And so we can begin to actually tease apart the cause

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of this extinction, the effects of climate change,

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and human arrival on the impacts on these animals

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and why they may have gone extinct.

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Saber toothed cats were incredibly successful

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for a very long time, and some scientists believe

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that we're just in a lull between Smilodon

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and the emergence of a new species.

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Today, we only see one single feline species

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alive that has a similar skull morphology

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like that of the saber tooth cat.

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The clouded leopard is a mid-sized cat

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that prowls the tropical forests of Indonesia

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with very elongated canine teeth.

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If they're able to more effectively hunt

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by having elongated canines, then that could get

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sort of fixed in that population and you could see

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these elongated canines yet again.

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00:13:56,810 --> 00:13:59,800
Long killing fangs evolved so many times

265
00:13:59,800 --> 00:14:01,720
during the past twenty million years

266
00:14:01,720 --> 00:14:03,770
that there's every reason to believe

267
00:14:03,770 --> 00:14:07,783
that a new saber toothed cat just might roam Earth again.

268
00:14:09,690 --> 00:14:13,057
(intense music)

269
00:14:13,057 --> 00:14:15,807
(tiger growling)