到长相奇特的镰刀龙分
to the bizarre Therizinosaurs...
树居的小盗龙
..the extraordinary tree-living Microraptor,
到巨盗龙
to the weird Gigantoraptor.
他们进化成各种形状大小
They evolved into an incredible range of shapes and sizes.
霸王龙无疑是兽脚目恐龙中
The tyrannosaurs were the most successful
最成功的一种
of the theropod predators.
因为在霸王龙生存的地方
And once tyrannosaurs dominated in an area,
其它的肉食恐龙都消失了
many other meat-eating dinosaurs simply disappeared.
但是那些改变了食物来源的却生存了下来
But those that had changed their diets flourished.
蒙古 8500万年前
Mongolia, 85 millions years ago.
一种恐龙在这儿繁荣生息
One group of dinosaurs thrives here
即使生活在霸王龙的威胁之下
despite the fact that they live in the shadow of a deadly tyrannosaur.
杂龙 同时吃肉的植物的杂食恐龙
These are Oviraptorids, omnivores that eat animals and plants,
所以他们不需要和强者争抢食物
and so don't compete directly for food with the biggest of killers.
这样的好处是显而易见的
And the benefits are clear,
因为他们长得非常巨大
because some of these creatures become huge,
比如八米长的巨盗龙
like the eight-metre Gigantoraptor.
但是这些恐龙还有其它绝招
But this group have another trick to help them survive,
就是他们筑巢的方式
the way they nest.
1994年在蒙古
In Mongolia in 1994,
人们发现了有巨大恐龙蛋的巢
a nest of very large dinosaur eggs was discovered.
一共有二十多枚蛋
An array of more than 20 eggs
被成对的摆放在浅坑周围
arranged in pairs around the edge of a shallow pit.
这是人们找到过的最大的恐龙蛋
They were the biggest dinosaur eggs ever found.
当发现了蛋里的胚胎后
When an embryo was found preserved within an egg,
几乎可以肯定
it proved that the nest, eggs and embryo
这个巢是属于巨盗龙的
were almost certainly those of Gigantoraptor.
但是筑巢对于恐龙是危险的
But nesting makes an animal vulnerable.
独龙
Alectrosaurus.
但是面对两只巨盗龙
But against a pair of Gigantoraptors,
一只五米长的霸王龙没有多少胜算
a five-metre tyrannosaur has little chance of success.
当我们进一步了解了在蒙古的发现后
As Mongolia has given up it secrets,
得到了更多关于这种恐龙的证据
we have learnt more and more about these extraordinary creatures.
2005年 一块化石上 一只恐龙
In 2005, one particular fossil was found to contain two eggs
正准备生下两颗蛋
within its body cavity, ready to be laid.
其它一些更神奇的发现
Even more amazing were a number of other finds
揭露了这些恐龙的筑巢行为
that revealed the nesting behaviour of these dinosaurs.
三只恐龙同时坐在蛋上
Three dinosaurs were discovered, all sitting on top of nests of eggs -
这些恐龙坐在巢的中心
the dinosaurs sitting in the centre of the nest with their long arms
展开双翼保护周围的蛋
spread out to protect the pairs of eggs arranged around them.
这些恐龙在孵化
These dinosaurs were brooding.
对蛋的保护增加了蛋的孵化成功率
Looking after their eggs increases the chance of them hatching.
大的蛋也意味着幼龙的发育更完全
And having large eggs means the hatchling is more developed,
不易成为捕食者的猎物
making it less vulnerable to predators.
但是孵化却要花费更久的时间 长达80天
But it takes longer to hatch - up to 80 days for Gigantoraptor.
这段时间内 蛋和父母都
A time when both egg and the brooding parent
处在危险之中
are permanently at risk.
小的盗蛋龙只是聒噪的小角色
Smaller Oviraptors are no more than a nuisance.
而大型捕食者就是另外一回事了
Larger predators are a different story.
父母寸步不离的保护巢穴
Unwilling to leave the nest, the adult protects its offspring,
首先 通过藏
first, by hiding...
如果失败了 只能通过战斗
..and if that fails, it goes on the offensive.
对于巢穴的保护
Protecting the nest
意味着巨盗龙的幼龙有更大的生存希望
means Gigantoraptors' young are more likely to survive.
现在看来 对于巢穴的保护
It now seems clear that the instinct to nurture
是有着悠久历史的
and care for a nest of eggs had its origins with the dinosaurs.
这样的行为非常成功
It's a behaviour that was so successful,
以至于今日的鸟类还在沿用
it's still widespread today with birds.
但是化石却显示了另外的发现
But the fossils show something else.
这些动物死的时候都坐在巢穴上
These animals all died sitting on their nests.
看来威胁不止来源于捕食者
It seems that the threats don't always come from predators.
有时危险源自最不可能的地方
Sometimes the real danger comes from the most unlikely places.
这些恐龙都是被活埋的
These dinosaurs were all buried alive.
恐龙星球是多元化的星球
Planet Dinosaur was an incredibly diverse and varied place,
这些生物占领了地球的每一个大洲
with these creatures able to colonise every continent on Earth.
不停地进化改变
Continually evolving and changing,
它们对地球的统治是不容置疑的
their dominance of life on Earth was absolute.
但是这一切都烟消云散了
Yet, they were doomed.
毁灭是由一颗撞击地球的小行星引起的
Their downfall was caused by an asteroid smashing into the Earth.
速度是子弹的二十倍
Travelling 20 times faster than a speeding bullet,
直径十五千米
15 kilometres across,
砸进了墨西哥湾
it slammed into The Gulf of Mexico.
这次碰撞释放的能量比十亿颗核弹还强
The impact released more energy than a billion atomic bombs.
最初引起了森林大火
The initial impact triggered wild fires,
巨大的地震和海啸
massive earthquakes and tsunamis.
但是最为致命的是遮天蔽日的尘埃
But most devastating was the debris blasted high into the atmosphere.
使地球陷入了长达几个月的黑暗中
This shrouded the planet in a cloak of darkness that lasted for months,
没有了阳光
cutting off sunlight.
地球陷入了永恒的黑暗
The Earth was thrown into almost permanent night.
从这次碰撞中生存下来的动物
Animals that survived the blast
仍然面对着严酷的考验
were now faced with their greatest ordeal,
食物链完全断裂
as a devastating chain of events was set in motion.
没有了阳光 很多植物都死了
Deprived of light, many plants died.
素食恐龙是第一个受影响的
Plant-eaters like this Magyarosaurus are the first to be affected.
没有了食物 恐龙纷纷死去
With no food, the biggest succumb first.
新生长出来的植物带来了一丝希望
Fresh growth of plants offers a glimmer of hope,
小型的素食恐龙得以存活
allowing smaller plant-eaters to scratch out a living.
但是不会支撑太久
But these aren't enough to sustain anything for long.
食腐动物的境况要好得多
Scavengers initially have an easier time of it.
随着素食恐龙由于饥饿死亡
As the plant-eaters succumb to starvation,
产生了大量的食物
there is a glut of food.
但是这只是一时的盛宴
But this surplus is an illusion.
随后 食腐动物也陷入了饥饿
Once gone, scavengers will starve, too.
整个食物链完全断裂
The impact resulted in the collapse of whole food chains,
毁灭性的打击不仅限于恐龙
and the extinction didn't just affect dinosaurs.
整个地球的生物都受到了打击
Virtually all life on Earth was affected.
大约60%的物种消亡
More than 60% of all species were wiped out.
但是恐龙的灭亡并非意外
Yet the extinction wasn't a lottery.
有一项决定了恐龙的命运
One factor more than any other determined the dinosaur's fate.
体型
Size.
所有超过25千克的动物都死了
On land, no animal weighing more than 25 kilograms survived.
没有足够的食物来支持大型动物
There just isn't enough food to sustain large animals.
成也萧何
Ironically, it's the very thing that make dinosaurs so iconic
败也萧何
that condemns them to extinction.
近年来的发现
The finds and discoveries of recent years
描绘了令人惊愕的发现
have painted a staggering picture.
恐龙有着强大的适应能力
Dinosaurs were incredibly adaptable,
以及不俗的求生能力
with an astonishing capacity for survival.
忍♥受着大♥陆♥的断裂 海平面的上升
Enduring the break-up of continents, sea-level rises
以及气候的变化
and countless changes in climate,
他们持续的繁衍发展
they continued to diversify and thrive.
在陆地 在海洋
On land, in water,
树木甚至是天空
among the trees and even in the skies.
他们占领了所有的大♥陆♥
They conquered every continent,
统治地球长达1亿5000万年之久
dominating life on Earth for more than 150 million years.
他们是有史以来最成功的动物
The most successful animals the world has ever known.
仅仅是一个无法预料的天外来客
It was only with an unprecedented extraterrestrial impact
就见证的这伟大恐龙星球的消亡
that finally saw the end of Planet Dinosaur.