This is a story about a deadly tooth, and a paleontologist named Jack Sang.
JT: I like to study animals that look weird or awesome.
And few animals look as weird and awesome as the saber tooth cat, Smilodon fatalis [SMILE-oh-don
fat-TALL-is]
JT: Their mouths are their weapons.
And that's part of the draw to study them.
What were these animals doing they're so weird looking.
Imagine you're in Los Angeles … 30,000 years ago.
JT If you came across a Smilodon it would probably look like a mountain lion on steroids.
And the teeth would not be hidden from under the fur; they would be showing.
So it’s pretty scary looking.
And if you’re close enough to see those features you’re probably…
uh… dead.
THE MECHANICS OF THE MOUTH SWORD
These teeth were not to be trifled with.
Some could grow to nearly a foot long.
JT: And oftentimes they are serrated just like steak knives.
The saber has evolved six times in different lineages..
JT: That’s 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 even suggested:
JT They could not hunt because they looked so awkward.
But Jack says that theory couldn't cut hot butter.
JT: If you were a scavenger you probably would not need that extreme of a tool.
Another idea is that they didn’t use them to hunt, they just looked sexy with them.
But most agree that these mouth daggers had but one purpose:
JT: Killing tools.
Stabbing tools.
Or cutting tools.
You kind of make this surgical cut on the neck, hopefully either severing a major artery
or the windpipe.
And they can actually use the back teeth, the cutting teeth, to just chew off pieces
of their prey.
If your blood is starting to run cold from terror and revulsion…
JT: Pretty much.
And people -- well I don’t know if other people do it but I do in my office-- I try
to reenact in my office with different skulls when nobody is looking.
MAMMAL THEATRE HOW DO YOUR WEAPONS GROW?
So the cat would prow very low and slowly, stealthily to their prey.
And at the last moment it would probably just hop.
And they use their powerful neck musculature to drive those canines in to the throat.
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?
To figure it out, they looked at fossils from the La Brea tar pits in Los Angeles.
They employed a combination of technologies: CT scans…
JT: Because CT uses X-rays to blast through these fossils or bones…
And created 3-D images of the teeth.
They also looked at the chemical composition of the teeth.
This tells them about the tooth growth rate.
See, teeth absorb nutrients as they grow.
JT: And there’s some natural fluctuation in the composition of the elements over the
course of the year that you can actually see a seasonal cycle.
And they found Smilodon sabers grew about 6 millimeters per month.
JT: That doesn’t sound like a lot but if you put it into context, human fingernails,
for example, grow at 3.4 mms per month.
And lions, their canines grow half as fast.
But it still takes Smilodon longer than modern big cats to finish growing their extra long
teeth.
JT: To grow a seven inch saber it would take up to three years.
And this tells us a little about the life of baby saber-tooths.
JT: Since it took longer to grow these weapons, it probably would have been beneficial for
these cubs to be following their parents, or for their parents to care for the cubs
for a longer period of time.
And this is the wonder of modern paleontology.
You can start to understand, and even imagine the life of a 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.