Allosaurus are cooperative hunters.
异特龙是合作猎手。
So as two of them move down to take on their adversary head-on, the third moves off in a different direction in an effort to outflankthe Ceratosaurus.
两头异特龙从正面向对手靠近，第三头则从另一个方向试图包抄这头角鼻龙。
We see this sort of ambush maneuver in modern lions and, sometimes, wolves.
我们能在现代狮群中看到这类伏击,有时候狼群里也有。
If you can keep your opponents attention focused in one direction, it allows for a surprise attack from the other.
要是能让把对手的注意力吸引到一个方向，这就让其它同伴能发动突袭。
One of them took advantage of the Stegosaurs' vulnerable position, and uses him as a platform.
它们中的一头利用了无助的剑龙,并把它当做平台。

The Ceratorsaurus begins to move away from the Stegosaurus.
角鼻龙开始从剑龙处后撤。
With an incredible force, the third Allosaurus crushed the unsuspecting Ceratosaurus.
第三头异特龙把毫无准备的角鼻龙猛地摔了出去。
We now know that some stegasaurus could have as many as eight spikes on their tail.
我们现在知道有些剑龙尾巴上的尖刺多达八根。
The massive weight on the female Stegosaurus causes her body to lean forward, this frees her tail.
雌性剑龙身上的巨大重量让它的身体向前倾，这就解放了它的尾巴。
The moment she feels her tails become free, she swings it with every bit of remaining energy she has and it lands a direct hit.
它等到尾巴能够活动时，立刻用尽所剩力气猛地抡起尾巴直接击中了对手。
The location of the bones tells the story.
击中的骨头位置说明了一切。
One Allosaurus down.
一头异特龙倒下了。
A few steps away, the motionless body of the Ceratosaurus.
几步之外是一动不动的角鼻龙。
A Stegosaurus struggles to free herself from this muddy trap.
一头剑龙挣扎着想从泥里脱身。
Next to her, the lifeless body of her offspring.
它的旁边是它孩子毫无生机的尸体。
A hundred meters away, another dinosaur arrived.
一百米之外另一种恐龙出现了。
A family of Camarasaurus moves down to the lakebed.
一家圆顶龙来到湖床。
Leading them is a huge male.
带领它们的是一头巨大雄性。
Its sheer size is enough to deter almost any attacker.
仅仅是它的体型就足够吓退几乎所有的攻击者。
The Allosaurus are now faced with a difficult choice.
异特龙现在面临艰难抉择。
Do they continue their attack on the Stegosaurus or do they dare take on something as huge as a Camarasaurus?
是继续进攻这头剑龙还是冒险攻击巨大无比的圆顶龙？
I would say that under normal circumstances, a Camarasaurus was such a big animal that it didn't really have to worry about attack very often.
我得说在一般情况下，圆顶龙个头儿实在太大，基本上不用担心会被攻击。
We certainly know that sometimes they get stuck in the mud.
我们知道它们有时也被困在泥里。
And in a situation like that, if it's isolated from the rest of the herd, Allosaurus may have taken a chance.
在这样的情况下，如果它和群体里其它成员分开了，异特龙也许会冒险一试。