Hell Creek, Montana. 68 million years ago.
蒙大拿州，海尔克里克。六千八百万年前。
Prehistoric plant eaters live every day with a target on their back.
史前世界的食草动物每天都生活在弱肉强食的环境中。
To avoid becoming dinner, they rely on specialized evolutionary adaptations,
为了避免成为他人的晚餐，它们就得依靠各自专门的进化适应能力
internal armor, advanced designs, and armaments tougher than anything found on animals today.
内部的护甲，先进的脑部构造，以及当今世界的动物无法企及强大武装。
These are animals that have defenses.
这些动物具有很好的防御性。
Herbivores do seem to be marvels of engineering.
这些食草动物仿佛就是工程学上的奇迹。
Very dangerous, heavily armed, heavily armored targets.
它们都有厚重的铠甲并且全副武装，相当的危险。
A Triceratops can hold its own against almost any predator.
三角龙可以独自对抗任何食肉动物。

With three horns and a bony shield, even a T. Rex keeps its distance.
凭借三个犄角和骨质盾牌，即使是雷克斯霸王龙也会对它敬而远之。
An Ankylosaurus is completely different.
甲龙则完全不一样。
It may be an herbivore, but it has the tools to stop an attacker dead in its tracks.
也许它只是食草动物，但它的装备能让攻击者有来无回。
Ankylosaurus was a walking tank-- a massively armed and armored animal.
甲龙就是一部移动的坦克，全副武装并且防护严密。
Nine meters long and weighing four tons, Ankylosaurus's home is the American West.
体长九米，重达四吨的甲龙栖息在美洲大陆的西部。
Interesting thing about Ankylosaurus which makes them kind of cool is that their pelvises have been modified so it's very broad.
有趣的是甲龙之所以这么酷是因为它的盆骨进化得非常宽。
They have an enormous gut and they probably in engaging what's called fermentation digestion
它有一个巨大的腹部，在里面可能一直在进行着所谓的发酵消化，
and we see their in uh...like cows and horses and what not in.
现在的牛、马和其它动物也有类似的功能。
They use bacteria break down the soilous material.
它们利用细菌来分解草料。
The problem is that you probably was not wanna be downwind of an Ankylosaurus just probably you stay stinking machine walking its way to the forest.
问题在于你可能不想待在甲龙的下风处，你可能就是看着这台臭味制造机独自走进森林。
Digesting plant fibres is the hardest job.
消化植物纤维是一样艰巨的任务。
In the ecosystem an Ankylosaurus tank that job, which is why need that the enormous bulk gigantic stomach and some divided intestines that means...you are slow.
在生态体系中，甲龙要想完成这个任务就必须要有巨大的身躯硕大的胃部和一些分离的肠道，这意味着你行动缓慢。
You are very slow and you have to feed 12,15,18 hours a day.
你行动非常缓慢，每天要花上十二至十八个小时来进食。
Invulnerable for most of the day and therefore you have to have static armor.
为了在大部分时间内做到无懈可击，所以必须要披上厚重的铠甲。