Sabers were closing in on him.

几只剑齿虎包围了他。

And then there was the most infamous cat of all, the sabertooth.

而另一个例子就是鲜为人知剑齿虎。

Well, well-meaning caveman, imagine a saber-toothed tiger is running after you and you need to respond.

好吧，善意穴居人，想象一只剑齿虎在追你，你需要做出反应。

This giant tooth right here is the canine tooth of a saber-toothed cat from an animal called Smilodon.

这个巨大牙齿是剑齿虎犬齿，这是一种有巨大牙齿猫科动物。

We're at the top of the food chain, we don't have to defend ourselves from saber-toothed Tigers anymore.

现在人类处于食物链顶端，不必再去保护自己受剑齿虎威胁了。

Here is the skull of a giant sloth and vertebrae and bones from giant saber-toothed cats and dire wolfs.

这是一个巨大头骨，巨大剑齿虎椎骨和惧狼骨头。

Yeah, what I'm holding here in my hand is pretty much what was walking around inside of the living Smilodon.

对，我现在手里拿着就是活着剑齿虎身体里长出牙齿。

You want the arteries that supply your muscles to dilate so that you can run away from the saber-toothed tiger.

你希望供应肌肉动脉扩张，这样你就可以逃离剑齿虎。

Just remember to be wary of the saber-toothed tigers that would be running around.

请记住要提防四处奔跑剑齿虎。

These stripes serve to warn off most attackers, but perhaps the sabertooth is yet to learn exactly what they mean.

这些条纹用来警告大多数捕猎者，但是这只剑齿虎似乎还没有意识到这些条纹具体含义。

First things first, though - what does sabertooth actually mean?

不过，首先要做是——剑齿虎到底是什么意思？

Why are saber-tooth tigers extinct and regular tigers not extinct?

为什么剑齿虎灭绝而普通老虎没有灭绝？

He's an overexaggerated smilodon with comical green hair.

他就像个长着绿毛极度夸张剑齿虎一样。

Technically speaking, a sabertooth is simply any animal with extremely elongated canine teeth.

从技术上讲，剑齿虎就是任何具有极长犬齿动物。

If our ancestors had not feared cliff-edges or sabre-toothed tigers, we might not be here today.

如果我们祖先没有害怕悬崖边缘或剑齿虎，我们今天可能就不会在这里。

All right. So why are saber-toothed tigers extinct but regular tigers are not extinct?

好。那么，为什么剑齿虎已​​经灭绝，而普通老虎却没有灭绝呢？

That's more than mammoths or saber tooths or even today's ubiquitous coyotes.

这不仅仅是猛犸象或剑齿虎，甚至是今天无处不在土狼。

But when it comes to saberteeth, the question is… why?

但说到剑齿虎，问题是… … 为什么？

Well, there's been no shortage of theories about how sabertooths used their fangs.

好吧，关于剑齿虎如何使用尖牙理论并不缺乏。

This may be the ice age, but by midday, temperatures soar, drawing another predator to the spring to drink—the notorious saber-toothed cat.

这可能就是冰河时代，但是到了中午，气温则迅速上升，另一只捕猎者也来到了泉水处饮水——令人闻风丧胆剑齿虎。