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

始新世南极洲的其他居民可能 也来自南美洲。

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.

到始新世， 些大陆上几乎所有的灵长类动物都灭绝了。

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

植物区的地区发现，但它们的科显然 要远得多 在始新世时广泛存在。

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

尽管白垩纪时的小行星灭绝了居统地位的恐龙，但哺乳动物却一直到1000万年后的始新世才真正兴起繁盛起来。

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

显然，南极洲的生物多样性 在始新世之后受到了打击。

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

在美国，始新世早，Boverisuchus 已经完并准备好奔跑。

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

在始新世时，气候 开始慢慢变冷。

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，始新世-渐新世过渡标志着球变冷和冰川作用的第一个主要时。

But what happened to these Eocene animals?

但是些始新世动物发生了什么？

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

5500 万年前的古新世-始新世极热非常温暖，以至于鳄鱼在北极圈的水域中游来游去。

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 比始新世早。

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，始新世和 渐新世早是球降温的时。

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

所以考虑到它的大小，它能够支持 始新世许多不同的生态系统。

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

因此， 当始新世结束时，北美不再有适合灵长类动物的栖息地。

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

他们在大约 4200 万年前的始新世中到达南美洲。

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

一变暖时被称为古新世-始新世极热事件或PETM，可能是由多种自然因素造的。

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，始新世后半也发生了巨大的环境变化。

Antarctica in the Late Eocene, was home to at least two more species of giant penguin.

始新世的南极洲是至少两种巨型企鹅的家园。

In the early Eocene Epoch, probably before mustelids appeared, our planet had a warm climate.

在始新世早，可能在鼬科动物出现之前，我们的星球气候温暖。