The Cretacious period isn't as hot as the Jurassic.

白垩纪没有侏罗纪炎热。

The temperatures are still hotter than today, but the relatively cooler climate allows the dinosaurs to be more active.

气温仍比如今要高，不过相对凉爽的气候让恐龙更加活跃。

This is an advantage for the meat eaters who expend more energy in a fight than the plant eaters.

这对于肉食者来说是个优势，它们在搏斗时比植食动物要消耗更多热量。

The Albertosaurus also has a cavernous stomach.

阿尔伯特龙的胃也如同无底洞。

It could eat a cow in a single meal.

它一顿能吃下一头牛。

Its endless appetite drives it to kill.

它无尽的胃口驱使它去杀戮。

The Albertosaurus paces back and forth, pushing the herd into a tighter formation.

阿尔伯特龙前后踱步，将角龙群逼成更紧凑的队形。

From experience it knows that if they're packed in too tight, then they'll lose their ability to move independently, and that's when he'll strike.

经验告诉它如果角龙之间挤得过紧，它们就会失去独立移动的能力，那时就可以开始攻击了。

The brain of the Pachyrhinosaurus can only think of one thing at a time.They react rather than plan.

肿鼻角龙的大脑一次只能思考一件事。它们靠的是反应而不是计划。

If they're focused on an attacker, they are not attuned in to their environment.

如果它们关注攻击者，就留心不到它们所处的环境。

One by one, the Pachyrhinosaurus are being pushed into the river as the herd moves back.

肿鼻角龙群在向后退的时候，一个个坠入河中。

Normally these dinosaurs would be able to swim without any trouble, but now they are in panic mode and it's every dinosaur for himself.

通常这些恐龙能够不费力地游泳，不过现在它们处于恐慌状态，每头恐龙都在努力求生。

In their struggle to get away from the Albertosaurus, they begin to drown each other.

为了挣扎逃离阿尔伯特龙，它们开始将同伴淹死。

The Pachyrhinosaurus can swim like a dog, holding its head above water and paddling with its feet.

肿鼻角龙能像狗一样游泳，把头部抬出水面用脚来划水。

But this is impossible when they are tightly packed together.

但这在它们紧紧地挤在一起时，那便不可能。

Albertosaurus is not a good swimmer.Its small arms are useless in the water, leaving it to rely on its two powerful legs.

阿尔伯特龙不是游泳健将。它短小的前肢在水中没有用，只能靠两条有力的后腿。

Even though the Albertosaurus is capable of swimming, there is no way it's going to get into a flooded river.

尽管阿尔伯特龙有能力游泳，它绝不会进入泛滥的河水中。

But the sight of the herd floating downstream is too much for him to ignore, so he heads off to follow the river and look for an opportunity to snatch one from the water.

不过看到角龙群漂向下游，对它来说忽视它们太难了，所以它开始沿河跟随找机会从水中抓住一头。

The protective frill of the Pachyrhinosaurus is capable of showing color.It may have reflect its emotions.

肿鼻角龙的保护性褶皱能够显示颜色。也许反映了它的情绪。