But not all plant eaters in the Cretaceous live as a group. Ankylosaurus are loners.
然而白垩纪并非所有食草动物都是群居的。甲龙就是个独行侠。
They depend on a powerful tail club and steel-like body armor to defend themselves.
它们靠尾部有力的尾锤和全身钢铁般的铠甲保护自己。
Without the herd to watch your back, Ankylosaurus has to watch its own.
没有同伴的互相帮助，甲龙全靠自己小心。
That's a job made even harder, as its worst enemy, T. Rex, can hunt under the cover of darkness.
更难的是，它的劲敌，雷克斯霸王龙能在夜幕的掩护下猎食。
Fortunately, an Ankylosaurus has another effective weapon in its armory - a highly refined sense of smell.
幸运的是甲龙还有个绝招，那就是极其敏感的嗅觉。
The nasal region of Ankylosaurus and its kin is one of the most specialized parts of its anatomy.
甲龙及其亲缘物种的鼻子是它全身最特殊的一部分。
For an Ankylosaurus, a T. Rex's distinctive odor is a dead giveaway.
对于甲龙，雷克斯霸王龙发出的独特气味就是死亡的警示。
This is an animal for whom the sense of smell was more important, potentially, than the sense of vision.
嗅觉比视觉对于它们而言更加重要。

Ankylosaurus' nasal passages wind through the skull, significantly increasing their surface area.
甲龙的嗅觉通道蜿蜒在头骨里，有效地增加了其感知面积。
This enlarged space is populated by millions of odor receptors.
其中还布满上百万个气味感受器。
Complicated, crazy-straw, tortuous nasal passageway that went from the nostrils,
复杂而弯曲的鼻道从鼻孔开始
made several loops through the snout before it went down into the throat.
在鼻部环绕数圈一直蜿蜒到颈部。
Ankylosaurus' supersensitive nose can pick up a carnivore over two miles away.
甲龙极其敏感的嗅觉能在两英里外就辨别出食肉动物的气味。
If it could smell a Tyrannosaurus coming, it's got an early warning,
当它嗅到霸王龙的气味，早早获得敌情，
and so it can begin to react appropriately.
便可以随之采取相应的对策。
For a hungry T. Rex, it means a meal has simply vanished into thin air.
对饥饿的雷克斯霸王龙来说，这就意味着一顿美餐化为乌有。
Never underestimate a vegetarian.
千万不能低估了食草动物。
Parasaurolophus and Sauroposeidon rely on the numbers to spot predators before they attack.
副栉龙和波塞东龙靠群居来警惕食肉动物的攻击。
Ankylosaurus has an armory of senses to keep carnivores at bay.
甲龙的秘密武器是它的嗅觉可以御敌于千里之外。
But no matter how clever an herbivore may be,
但无论食草动物多聪明，
no matter how many tools they have at the ready, sometimes their time is up.
无论它们有什么本领，有时死神依然会降临。
For herbivores, keeping one step ahead of the competition is never ending struggle.
对食草动物来说，在生死竞争中领先一步就要永远保持战斗状态。
T. Rex was designed by natural selection to overcome those formidable defences.
雷克斯霸王龙在自然选择下能够对抗这些坚不可摧的防御手段。