Though the Cretaceous asteroid cleared the stage, mammals did not really get going until 10m years later, in the Eocene epoch.

尽管白垩纪时期的小行星灭绝了居统治地位的恐龙，但哺乳动却一直到1000万年后的始世才真正兴起繁盛起来。

Eocene, so, by about 40 million years ago, many of them had gone extinct.

，因此，到大约 4000 万年前， 其中许多已经灭绝。

By the late Eocene, practically all of the primates on those continents died out.

到始世晚期， 这些大陆上几乎所有的灵长类动都灭绝了。

Floristic Region, but their family was clearly much more widespread during the Eocene Epoch.

的地发现，但它们的科显然 要远得多 在始世时期广泛存在。

Other residents of Eocene Antarctica probably came from South America as well.

始世南极洲的其他居民 来自南美洲。

In the United States, Boverisuchus shows up fully-formed and ready to run in the early Eocene.

在美国，始世早期，Boverisuchus 已经完全成形并准备好奔跑。

Around 34 million years ago, the Eocene-Oligocene Transition  marked the first major period of global cooling and glaciation.

大约 3400 万年前，始世-渐世过渡标志着全球变冷和冰川作用的第一个主要时期。

Over the course of the Eocene epoch, the climate slowly began to cool.

在始世时期，气候 开始慢慢变冷。

Clearly, Antarctica’s biodiversity took a hit after the Eocene.

显然，南极洲的生多样性 在始世之后受到了打击。

The Paleocene-Eocene Thermal Maximum, 55 million years ago, was so warm, crocodiles swam the waters of the Arctic Circle.

5500 万年前的古世-始世极热期非常温暖，以至于鳄鱼在北极圈的水域中游来游去。

What we do know is that the late Eocene and early Oligocene was a time of global cooling.

我们所知道的是，始世晚期和 渐世早期是全球降温的时期。

As a result, our world is warming faster than it did back in the Eocene.

结果，我们的世界变暖的速度 比始世早。

So given its size, it was able to support many different ecosystems in the Eocene.

所以考虑到它的大小，它够支持 始世许多不同的生态系统。

But what happened to these Eocene animals?

但是这些始世动发生了什么？

So by the time the Eocene Epoch was over, North America no longer had the right habitat for primates.

因此， 当始世结束时，北美不再有适合灵长类动的栖息地。

This period  of warming, known as the Paleocene-Eocene Thermal Maximum or PETM, was likely caused by  a combination of natural factors.

这一变暖时期被称为古世-始世极热事件或PETM，是由多种自然因素造成的。

And they arrived in South America by the middle Eocene Epoch, around 42 million years ago.

他们在大约 4200 万年前的始世中期到达南美洲。

And a big environmental change was also underway in the last half of the Eocene, thanks to the chemistry of mountain-building.

由于造山的化学作用，始世后半期发生了巨大的环境变化。

You see the Amazon formed during the Eocene epoch, up to 56 million years ago when the whole world was a lot warmer and wetter.

你以看到亚马逊河形成于始世时期，距今约5600万年前，当时的地球要温暖得多，湿润得多。

Or there's the Eocene, more than 34 million years ago, a hothouse time during which the continents drifted into their present configuration.

或者是超过 3400 万年前的始世，这是一个温室时代，在此期间大陆逐渐变成了现在的形态。