恐龙行星（2011）

控制土地是这些捕食者生存的关键
Dominating the land is the key to survival for these killers.
也许将会导致一场你死我亡的打斗
That can mean a fight to the death.
关于同种肉食性恐龙之间內战的证据
The evidence of in-fighting
让人印象深刻
between carnivores of the same species is dramatic.
对化石进行的医学检测发现
Forensic examinations of fossils has uncovered injuries
很多肉食性恐龙的头颅骨有伤
on the skull bones of many large carnivores.
咬痕更是家常便饭
Tooth puncture marks and gouges are remarkably common.
如此暴♥力♥的撕咬很可能是为了抢夺地盘
Such violent head- and face-biting is thought likely to be territorial.
因为有如此多的好处 对捕食领地的争夺
With so much to gain, fights over prime hunting territory
就变得很普遍了
would be commonplace.
对于这条获胜的鲨齿龙
For this victorious Carcharodontosaurus,
奖品就是获得对这些无畏龙的捕猎权
the prize is the hunting rights to these Ouranosaurs.
即使对于最快的捕猎者来说
Not an easy prey to catch,
无畏龙也不是容易捕捉的猎物
even for the fastest of predators.
但我们认为鲨齿龙有个潜在的优势
But we think Carcharodontosaurus has a hidden advantage.
2008年 对鲨齿龙骨头的详细分♥析♥
In 2008, detailed bone analysis
说明这些恐龙拥有
suggested these dinosaurs employed a system of air sacs.
有助于呼吸的气囊系统
Air sacs are used in breathing.
在呼吸的时候
They ensure that oxygen-rich air flows continually through the lungs
保证了氧气充裕的空气持续的流经肺部
when breathing in and out.
这是个很高效的系统 类似于鸟类呼吸系统
It's a very efficient system, similar to that of birds.
预示着像鲨齿龙这种恐龙
It implied that dinosaurs like Carcharodontosaurus
是高度活跃的捕食者
were highly-active hunters.
而它们也需要成为这样的捕食者
And they needed to be.
据估算这种大小的恐龙每天需要吃
It's reckoned that a dinosaur of this size would need to eat
最少60公斤的肉去维持生命
a minimum of 60 kilos of meat every day simply to survive.
大的捕食者依靠伏击他们的猎物生存
Big hunters rely on ambushing their prey.
尽可能缩小它和它猎物之间的距离
Closing as much distance between it and its chosen victim.
这条鲨齿龙不费吹灰之力
This Carcharodontosaurus doesn't waste energy
就把猎物追到手了
chasing the injured animal.
它第一次攻击就严重击伤了无畏龙
Its initial attack has critically wounded the Ouranosaurus.
现在它只需要耐心跟随等待
Now, it simply needs to follow and wait.
鲨齿龙是致命的捕猎者
Carcharodontosaurus were deadly killers,
但捕猎方式非你所想
but not in the way you might expect.
它的头颅骨相对较弱
Its skull was relatively weak.
电脑分♥析♥显示
And computer analysis has shown
鲨齿龙的体格不足以
that they're unlikely to be strong enough
稳住挣扎的猎物
to hold onto struggling prey.
他们的牙齿薄 像小刀
Their teeth were thin, like knives,
难以咬穿骨头
too weak to bite easily through bone.
但够锋利 而且有致命的锯齿 像鲨鱼的牙齿
But they were sharp, with deadly serrations, just like a shark's.
鲨齿龙本意就是"牙齿锋利的蜥蜴"
The very name Carcharodontosaurus means "sharp-toothed lizard".
我们认为鲨齿龙用头颅骨和牙齿
We think it used its skull and teeth
去猛砍进猎物的肌肉
to slash deep into the flesh of its prey,
导致重伤及严重失血
causing massive injury and blood loss.
加上速度配合 这样的攻击
Delivered at speed, such an attack could kill
避免了激烈的运动
without the need for an intense struggle.
这种捕猎方式非常有效
It's an efficient killing method
非常适合这种环境
and one that's perfectly suited to this environment.
然而季节变化后 情况就大不相同了
But success can look very different when a season changes.
白垩纪时期 北非有两位致命杀手
For a time, Cretaceous north Africa had two deadly killers.
利用不同的环境
By exploiting different environments,
他们可以完美的共存
they didn't compete and could coexist,
主宰自己的栖息地 棘龙就是这样的能手
dominating their chosen habitats. Spinosaurus was a specialist.
但这是有风险的
But this came with risks.
环境微弱的变化就会使它变得脆弱
Small environmental changes can make it vulnerable.
这里容易出现季节性干旱
And this area is prone to seasonal droughts.
河流枯竭时
When the river is dry,
棘龙就没了食物
Spinosaurus' usual food supply has disappeared.
其他动物守在残留的水塘边
Other animals retreat to a few remaining pools.
一些棘龙会很警惕
Some, the Spinosaurus would do well to be wary of.
小鳄鱼不会成为危险
The smaller crocs aren't the problem.
帝鳄是种体长达到十二米的巨型鳄鱼
Sarcosuchus a giant 12-metre crocodile.
这些爬行动物可以通过休眠
Reptiles like these can survive droughts
顺利度过干旱
by effectively hibernating during times of hardship.
棘龙却不行
Spinosaurus can't.
作为恒温动物
As an active hunter,
它的新陈代谢需要稳定的食物供给
its metabolism demands a regular supply of food.
它的狩猎技艺布置仅限于河流
Although it is a specialist, it isn't confined to the rivers.
在旱季里 它也能在陆地上捕食
In tough times, it too can hunt on land.
其他地区发现的棘龙化石
Spinosaur fossils from other parts of the world
让我们更细致地了解了它的食谱
have given us more details about their diets.
2004年
In 2004,
巴西发现的一具化石引起了人们的注意
a dramatic fossil was recovered from Brazil.
一节翼龙的颈椎骨
Part of the neck of a Pterosaur.
一颗牙齿嵌入在椎骨中
Embedded within one of the vertebrae was a tooth.
明确无误 它就是棘龙牙齿的形状
It was the unmistakable shape of a Spinosaur tooth.
另一只棘龙胃中有重爪龙
The stomach contents of another Spinosaur, Baryonyx,
在英格兰 发现有幼年禽龙的骨架
from England, was found to contain some bones of a juvenile Iguanodon,
一种植食性恐龙
a plant-eating dinosaur.
尽管他们有专长
In spite of their specialisation,
但显然棘龙不仅仅以鱼为生
clearly Spinosaurs weren't exclusively fish-eaters.
但捕猎并不易
But hunting and catching prey isn't easy.
尤其是猎物已经警惕时
Particularly when they're already alert.
在陆地上捕猎
Hunting on land,
棘龙被迫要与在同一环境中的
Spinosaurus is also forced into direct competition
大型猎手直接竞争
with any large predators living in the same environment.
在这里 唯一称得上对手的只能是...
And here, that can only mean one animal...
...鲨齿龙
..Carcharodontosaurus.
争夺猎物很平常
Contests over carcasses are common.
但胜出者缺永远是个未知数
But outcomes of such fights are far from guaranteed.
大型动物受伤是很严重的
Risk of injury for big animals is acute.
科莫多龙经常在争夺猎物中死去
Modern Komodo dragons are often killed in fights over carcasses.
比对手长三米多
More than three metres longer,
棘龙在体型和力量上有优势
Spinosaurus has size and power on its side.
但鲨齿龙的牙齿更具有杀伤力
But Carcharodontosaurus has the more lethal bite.
这次 棘龙获胜了
This time, the Spinosaurus triumphed.
但这两位杀手实力的高低
But the balance of power between these two deadly killers
仍是个未知数
is a precarious one.
2008年 一头棘龙的椎骨被发现
In 2008, a Spinosaurus vertebra was recovered.
部分高大的脊椎骨被折断
Part of the tall, neural spine of the bone was broken off.
看似是从中间咬断了
It appeared to have been bitten in half.
已被证明
It's been suggested
是鲨齿龙咬掉的
that the bite was inflicted by Carcharodontosaurus.
棘龙是最后也是最大的
Spinosaurus was the last and the largest
食鱼恐龙
of the fish-eating dinosaurs.
但最终 这些家伙灭亡了
But ultimately, these specialists were doomed.
无法控制的因素造成棘龙数量锐减
Something way beyond their control caused their downfall.
九千四百万年前 气候变了
94 million years ago, the climate changed.
全球海平面开始上升
Global sea levels began to rise.
棘龙生存的湿地和河流
The swamps and rivers that Spinosaurus thrived in
逐渐被吞并
gradually were lost.
这些领地的消失
With their loss,
使棘龙的生存环境变得很脆弱
Spinosaurus's specialism became a vulnerability.
已知最大的捕猎者
And the biggest predator
从地球上消失了
ever known to have walked the Earth disappeared.