史前星球（2022）

where vast pine forests flourish.
随着春天的脚步临近 树林中回荡着奇怪的叫声
As spring arrives, strange calls echo through the trees.
这是北美最全副武装的
The mating season has arrived
一种恐龙的交♥配♥季节
for one of North America's most heavily armed dinosaurs.
即三角龙
Triceratops.
每年 大量身型庞大的三角龙 会聚集在空地上
Every year, large numbers of these giants gather in clearings.
雌性们在此寻找理想的配偶
The females have come to choose a mate.
6吨♥重的雄性们通过激烈的争斗 来展示自己的实力
The six-ton males fight and display their strength.
这只年轻的雄性看起来正值盛年
This young male looks to be in prime condition.
它在炫耀着自己那壮观 长达1米的角
Showing off his spectacular meter-long horns...
和鲜艳的头饰
and his colorful head-frill.
它的角看起来完美无暇
His horns appear perfect.
尚未在战斗中受损
Not yet damaged by battle.
然而 对于雌性来说
To a female, however,
没有任何磨损的角 可能意味着潜在的致命弱点
the absence of any wear and tear might suggest a potentially critical weakness.
即缺乏战斗经验
A lack of experience.
这些聚会对三角龙来说至关重要
These gatherings are crucial events in the lives of Triceratops.
它们为成年三角龙 提供了一年中最好的繁衍机会
They provide the best chance in the whole year for the adults to become parents.
来这里的并非只有怀揣梦想的年轻三角龙
And young hopefuls are not the only ones here.
这只超过10吨♥ 年龄达30岁的雄性三角龙
A 30-year-old male weighing more than ten tons.
如果说有什么东西它拥有得多
If there's one thing that he has in spades,
那就是几十年来经历的战斗磨砺
it's decades of wear and tear.
虽然年岁已高
He may be old,
但它依然强壮 足以挑战年轻的对手 无论这个对手看起来多么健康
but he's still strong enough to challenge a young rival, however fit.
风险很高
The stakes are high,
可双方都不愿意让步
and neither is willing to back down.
经验丰富的老三角龙凭借4吨♥的体重优势
The veteran has a four-ton weight advantage...
和丰富的战斗技巧 稳操胜券
and the skill to make it count.
年轻三角龙的角不再完美
The youngster's horns are no longer perfect.
这头老三角龙的战斗力
The old bull's fighting prowess
显然给这头雌性三角龙留下了深刻的印象
certainly seems to have impressed this female.
对于失败者来说 交♥配♥季节已经结束
For the loser, the mating season is over.
然而 它新赢得的战斗伤疤也许足以吸引
However, his newly won battle scars might be just enough to attract a female
下一次聚集到这里来交♥配♥的一个雌性
next time the herds gather here to mate.
像三角龙这样的植食恐龙
For plant-eating dinosaurs like Triceratops,
在遍布北美大部分地区的广袤森林中 一年四季都能觅得
the vast forests that cover much of North America offer plenty to eat
丰盛的食物
all year round.
然而 对于生活在寒冷的 美洲大♥陆♥极北地区的动物来说
But for those that live in the cold far north of the Americas,
觅食就要困难得多
food is much harder to come by.
在北极圈内
Here within the Arctic Circle,
每年有三个月几乎看不见太阳
for three months of the year, the sun barely rises.
漫长的冬季过去 气温终于回暖
When its warmth finally returns after the long winter...
身披羽毛的似鸟龙迅速利用这一有利时机
feathered Ornithomimus are quick to take advantage.
这些敏捷的旅行者 是所有恐龙中奔跑速度最快的
These fleet-footed travelers are among the fastest runners of all dinosaurs.
能够行进很远的距离寻找新鲜植被
Capable of covering vast distances in search of fresh vegetation.
它们的速度如此之快 掠食者很难捕捉到它们
They're so fast that they're very difficult for predators to catch.
经过一个艰难的冬天
After a tough winter,
这头雌性白熊龙急需尽快捕获猎物
this female Nanuqsaur needs to make a kill soon.
它是霸王龙的小亲戚 但更为敏捷 关键是速度更快
A smaller relative of T. rex, but more agile and, critically, faster.
由于无处藏身 所以偷袭猎物是不可能的
There is nowhere to hide, so a surprise attack is impossible.
相反 它依赖于制♥造♥恐慌
Instead, she resorts to creating panic.
它需要选定一个目标
She needs to pick out a single target...
并坚定地追击
and stick with it.
似鸟龙的爆发力使它们占据优势
The Ornithomimus' bursts of speed just give them the edge.
每次失败的狩猎 都会进一步消耗宝贵的能量
Each failed hunt uses up more precious energy...
让这只雌性白熊龙更接近饿死的边缘
bringing her ever closer to starvation.
尽管春天已至
It may be spring,
但在如此靠北的地方 凛冽的寒风会迅速导致气温下降
but this far north, freezing winds can quickly cause temperatures to fall.
零星的降雪和露出地面的岩石 给了白熊龙第二次机会
Flurries of snow and a rocky outcrop could give the Nanuqsaur a second chance.
使其更难被发现
Now she's harder to spot.
每向前迈进一寸 它离成功就更近一步
Every inch forward brings her closer to success.
它锁定了目标
She selects her target.
它不能独享这份猎物
This prize is not only for her.
作为一个母亲
She is a mother.
这是它为孩子们准备的鲜肉大餐
Fresh meat for her youngsters.
也许这是几周以来的第一顿丰盛大餐
Perhaps the first for many weeks.
如果想让孩子们茁壮成长
If her babies are to thrive,
它将不得不一次又一次地复♥制♥今天的胜利
she will have to repeat today's success over and over again.
直至孩子们长大到能加入捕猎行列
Until her young are old enough to join her in the hunt
并最终自力更生
and eventually fend for themselves.
在这片遥远 或许是最具挑战的
Here, in this remote and perhaps most challenging frontier
北美大♥陆♥边疆
of the North American continent,
六千六百万年前
66 million years ago.
(揭秘《Prehistoric Planet》)
(为什么三角龙有扇状饰板 )
这是史前地球上最令人瞩目的头骨之一
This is one of the most dramatic skulls from our prehistoric planet.
它属于一种叫做三角龙的植食恐龙
It belonged to a plant-eating dinosaur called Triceratops.
从其后脑巨大的扇状饰板
This dinosaur is instantly recognizable
便能一眼认出这种恐龙
from the massive frill at the back of its head.
然而 在发现第一块化石140年之后
But 140 years after the first fossil was found,
科学家们仍在探寻
scientists are still asking,
“这个扇状饰板是干什么用的 ”
"What was the frill for?"
这些都是巨大的结构
These were enormous structures,
由大量骨骼和组织形成
so it's an enormous investment in bone and in tissue
(自然历史博物馆 保罗巴雷特教授)
同时需要很多肌肉支撑这些结构
and also in the muscular effort to hold these structures up.
所有这些投入肯定意味着 这些特征对动物的生活方式
All of this investment must mean that these features are very important
非常重要
to the animal's way of life.
但如何重要呢
But how?
三角龙化石上的受损证据显示
Evidence of injury on Triceratops fossils suggests
扇状饰板在防御和战斗中很重要
that the frills were important in defense and combat.
我们可以看到 头骨上的损伤
We can see lesions on the skull
(自然历史博物馆 苏珊娜梅德门特博士)
这些地方曾受到损害并已愈合
which are areas where the skull has been damaged and healed.
我们还能看到捕食者 从这扇状饰板上咬下一大块的痕迹
We can also see where a predator has taken a chunk out of a frill.
这可能表明我们看到的是某种防御结构
That might indicate that we're looking at some sort of defensive structure.
但故事并未就此结束
But the story doesn't end there.
另一种可能性是 扇状饰板用于吸引潜在伴侣
Another possibility is that the frill was used to attract prospective mates.
我们在现存的动物身上看到了类似现象
We see this in living animals
比如说 角这样的结构 显示出动物的健康状况
where structures like horns show off how healthy they are
以及谁更有可能繁衍出大量后代
and who's a good prospect for producing lots of young.
就驼鹿而言
For a moose,
大鹿角使雄性更具吸引力
having large antlers makes the male more attractive.
而这在性成熟时至关重要
Vital when it reaches sexual maturity.
那么 三角龙的扇状饰板 是否也具有同样的作用呢
Could the same apply to the Triceratops' frill?
如果仅用于防御
If it was only for defense,
我们会期望它们
then we would expect to see them develop
在青少年时期和成年时期 发展到相同的程度 但事实并非如此
to the same degree in juveniles as in adults, but we don't.
我们看到 它们在青少年时期要小得多
We see them being much smaller in the juveniles
直到很久以后 才真正发育成
and not really developing into the very, very large structures
非常大的成年结构
of the adults until much later.
(三角龙头骨发育)
这并不是唯一证据
This isn't the only evidence
表明它们被用于性展示
that they were used in sexual display.
扇状饰板的表面有很多凹槽
The surfaces of the frills are very heavily grooved.
这些凹槽可能携带着神经和血管
These grooves probably carried nerves and blood vessels
用于供应扇状饰板上皮肤的生长
that would have supplied the skin growing over those frills.
它的颜色可能非常鲜艳
This may have been very brightly colored,
这是一个很大的表面♥积♥ 可以让动物向潜在的伴侣炫耀
a big surface area for the animal to show off to potential mates.
科学家们如今认为
Scientists now believe that
三角龙最著名的特征确实具有多重功能
the Triceratops' best-known feature was truly multipurpose.
既是有效的攻击和防御工具
Very useful for attack and defense...
同时也是吸引异性的理想选择
but also ideal for attracting a mate.
无论对敌对友 这都是令人敬畏的景象
It would have been an awe-inspiring sight to friend or foe.