飞行巨兽（2011）

the thing you can see is not very well balanced at all.
这里你可以看到平衡不是很好控制的
Looks quite unstable, and worst still,
看起来相当不稳定 更糟糕的是
the tail is actually catching on the ground.
实际上尾巴已经拖在地面上了
So, now we can see him standing, in this four-legged pose.
这样 现在我们可以看到它四条腿站立的姿势
The winged membranes, which are attached to the hind limbs,
翼膜以某种方式
get in the way somewhat.
链接在了后肢上
It doesn’t look all that comfortable on the ground.
它看起来在地面上并不舒服
And in fact, when we look at the claws on the hands and the toes,
实际上 当我们看它手上的爪子的和脚趾时
we find that they’re really not well suited
我们发现 它们真的不适合
to life on the ground at all.
在地面上生活
Where’s he off to now?
那么现在的它怎么样呢
And now we see, it looks a lot more happy,
现在我们看到 它看上去更开心了很多
just hanging up there,
只是挂在那里
just as they would have done on trees and cliffs…
就像它们会挂在树木和峭壁上一样
Yeah. …back in the Jurassic.
是啊 回到侏罗纪
ATTENBOROUGH: So, early pterosaurs, with their long tails,
爱登堡: 所以 早期的翼龙长有长长的尾巴
probably spent most of their time hanging from vertical surfaces
它们的大部分时间都悬挂
like cliffs and the trunks of trees.
在悬崖和树木的树干上
But, if they were to spread beyond those environments,
但是如果想要生存在除此之外的环境中
they would have to change the shape of their bodies.
它们需要改变它们的身体形状
This fossil is 140 million years old.
这个化石有1.4亿年了
It has the enlarged head of an advanced pterosaur,
它具有比高级翼龙更大的头部
but its tail is different.
但是它的尾巴是不同的
It’s become much shorter.
它变得很短
And this short-tail species wasn’t alone.
而这个短尾巴的物种并非是独一无二的
It was clearly a very successful modification.
很明显这是非常成功的改进
There were many like it, with these new style short-tails
有很多像它有着新的短尾的风格
and reduced hind flight membranes.
并且减少了后飞行膜
Here, in France, at Crayssac, in the valley of the Lot,
在法国的Crayssac的一段山谷内
discoveries have been made that give us a unique insight
新发现的那些独具风格的
into the lives of these new style pterosaurs.
翼龙又有了新的见解
The short-tail creatures that appeared, are called “pterodactyls”.
这种新出现的短尾巴生物 我们称之为”翼手龙”
This is one of them.
这是其中的一只
The loss of the tail
简短的尾巴
had given them greater mobility in the air,
会带给它们更大的空气流动
but at the cost of a certain amount of stability.
也会带来一定的不稳定性
But also, the membrane between the two legs, have split.
但同时 两条腿之间的膜已经分开了
And that too, probably helped them in steering.
不仅如此 也许这也有助于转向
But flying was only part of their lives.
但是飞行仅仅是它们生活中的一部分
The sea in which these limestones formed,
这些石灰岩形成之前这里曾经是海
was here quite shallow.
但是很浅
And not far away, there was a beach.
在不远处还有一个海滩
And there, pterosaurs left particularly vivid evidence of their presence.
在那里 翼龙留下了许多其存在过证据
Fossils, not of the animals themselves,
化石并不是动物本身
but traces that only revealed themselves after dark.
但是它们只在黑夜中才会显现出来
The best way to look for fossils here, is at night.
在这里观察化石最好的时间是在晚上
Because then, you can control the light,
因为这时候你可以控制灯光
and makes sure that it shines almost horizontally
而且可以真切的看到
across the surface of the rock.
那些化石闪耀在整个岩石表面上
And so, expose every tiny little mark and ripple.
因此 每一个小小的标记或纹路都会显现出来
The muddy sand here was once soft, but firm.
这里的沙子曾经是柔软的 但是现在很坚固
And in consequence, it retained the tracks of animals that moved over it.
因此 它保留了动物移♥动♥后留下的轨迹
In fact, there are so many of them here,
事实上 这里有很多这种东西
that it seems that this particular beach was a kind of pterosaur runway.
这个特殊的沙滩似乎是一个翼龙用的跑道
Here is a track
这个足迹
that extends for 11 feet, between three and four metres.
延伸了11英尺 大概三四米之间
The most distinct tracks are made by the feet.
最明显的痕迹是用脚踩出来的
There’s one, there’s another,
这里有一个 这里还有一个
there’s another.
这边还有
But, outside these footprints,
但是 除了这些脚印之外
there are other, rather more indistinct prints,
还有其它的比较模糊的印记
which are made by the knuckles of the hand,
比如像是用指关节压出来的
without the little finger, which, of course,
当然 没有小指
is enormously extended, and it supports the wing membrane,
为了支撑它的翼膜 小指极尽的扩展
and is cocked up in the air.
竖起并指向空中
There’s one, there’s another,
这有一个 这有一个
there’s another, and there’s another.
这有一个 这还有一个
And when you examine the footprints,
当你考察这些足迹时
you can see that they have four toes.
你可以发现它们有四个脚趾
Not five, four.
不是五个 是四个
That’s a sign that these were made by short-tailed pterosaurs.
这是短尾翼龙的一个特殊的标志
And the distance between the feet varies.
脚印之间的距离
Sometimes it’s relatively short, sometimes it’s longer.
有的相对较短 有的却很长
And that’s because these animals moved at different speeds.
这是因为这些动物在以不同的速度移♥动♥
When they were moving at speed, they took bigger strides.
当它们加速时 会采用更大的步伐
So, these show, this marvellous deposit shows that
因此 这些奇妙的矿床显示了
short-tails, on the ground, were really very nimble indeed.
这些短尾翼龙是如何灵活的在地面上运动的
And that’s probably because the membrane between the legs,
这可能是由于它们双腿之间的膜
in the short-tails, has been divided.
已经被分离开了
So the legs have more freedom.
因此它们的脚变得更加灵活
So, the short-tail species were able to get about on the ground pretty well.
因此 短尾物种能到地面活动这是相当不错的
And that was important,
这是非常重要的一件事
because this enabled them to exploit new sources of food.
因为这使得它们有了更多的食物来源
Indeed, it might be the case that the future of the pterosaurs
事实上 我们确信
was assured, for some time at least,
在一段时间内 也许翼龙的未来
not by their ability to fly, but their ability to walk.
并不是由飞行而是由它们的行走能力决定的
This ability to walk
这种行走的能力
had a profound effect on pterosaur evolution.
对翼龙的进化产生了深远的影响
There’s evidence that from this time on,
有证据显示 从这一时间开始
all kinds of new species began to emerge
各种新物种开始
that fed on a wide range of different food.
逐渐被其它更多的物种当作食物
The short-tails proceeded to diversify into a great number of different forms,
短尾翼龙也逐渐演化出各种各样的形态
finding food in a great variety of places.
并且在各式各样的地方寻找食物
And you can tell what they ate by their skulls.
你可以从它们的头骨看出它们吃什么食物
This one for example,
就拿这一个来说吧
has, what look like a pair of tweezers on the front,
它有一个钳子一般的喙
and very rounded teeth.
还有着完美的牙齿
It is thought to have been able to dig out,
它们被认为能够挖掘出
cockles and mussels from the sand and crush them.
沙子里的蛤和贻贝并粉碎掉
So, this was walking on the ground.
所以 这就是能够行走的好处
This one, on the other hand, found its food while it was on the wing.
这一只 它能够一边飞行一边找寻食物
And that it dipped down and seized big fish,
它把嘴伸入水中 抓住鱼
which it stabbed with these teeth.
靠的就是它锋利的牙齿
And then, carried off in its jaws to rip apart, perhaps on the ground.
之后 也许它会把鱼刁回地面并撕咬吃掉
Others had dense rows of teeth that were so thin
还有一些长着细密的牙齿
they were scarcely more than bristles.
细细的就像刷毛一样
That enabled these animals to use their jaws like sieves
这就使得这些动物可以用它们的下巴
to filter out small crustaceans such as shrimps and other small morsels.
像筛子一样筛选出小型甲壳类如虾和俎
And some lost their heavy teeth altogether
有些翼龙甚至完全没有牙齿
and evolved beaks.
而演变成了喙
Adaptations like these were probably influenced,
这种适应环境所带来的影响
not only by the different ways of eating,
不仅仅是在吃的方式上
but by the universal need of all flying animals,
这些飞行动物为了需要
to keep their weight down to a minimum.
尽量把体重降低到最小
So, by about 80 million years ago,
因此 8000万年前
the short-tailed pterosaurs dominated the skies.
是短尾翼龙在统治着天空
Not only were they catching flying insects in mid-air,
它们不仅捕食在半空中飞行的昆虫
they were snatching food from the surface of the seas
还在海洋上空抢掠食物
and filtering it from the shallows.
甚至还在浅滩上找寻筛选食物
This was the pterosaur’s heyday.
这是翼龙的全盛时期
One species in particular symbolises their success.
这是一个物种达到全盛时的象征
It’s called Pteranodon.
它们就是无齿翼龙
It was the most common pterosaur of its time,
这是当时最常见的一种翼龙
and it was also very big.
它们的体形也很巨大
It measured about 18 feet from wingtip to wingtip.
根据测定 它们从一端的翼尖到另一端大概有18英尺
But how did such large animals manage to stay airborne?
但是这些大型动物是如何起降的呢
You can see the answer in this fossilized bone.
你可以从这个化石中找到答案
It’s hollow.
这是空心的
It’s been treated with acid, so that you can see inside it.
它已经用酸处理过 所以你可以看到里面的构造
And inside, it’s got a network of struts to support the bone.
在这里面 有一个网状的结构用以支撑骨头