Humans weren't at risk of dying out during the PETM, because we didn't exist.

在古新世–新世极热事件时人类并没有濒临灭绝的危险，因为我们还不存在。

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

在新世时期，气候 开慢慢变冷。

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 比新世早。

But what happened to these Eocene animals?

但是这些新世动发生了什么？

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

新世极的其他居民可能 也来自。

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

显然，极的生多样性 在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.

在国，新世早期，Boverisuchus 已经完全成形并准备好奔跑。

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

到新世晚期， 这些大陆上几乎所有的灵长类动都灭绝了。

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 新世许多不同的生态系统。

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

植区的地区发现，但它们的科显然 要远得多 在新世时期广泛存在。

But about 49 million years ago, in the mid-Eocene, the climate began to get cooler and drier.

但大约 4900 万年前，在新世中期，气候开变得更凉爽和干燥。

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

在新世早期，可能在鼬科动出现之前，我们的星球气候温暖。

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1000万年后的新世才真正兴起繁盛起来。

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，新世晚期和 渐新世早期是全球降温的时期。

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

因此， 当新世结束时，北不再有适合灵长类动的栖息地。

Let's rewind back to the Eocene, about 45 million years ago.

让我们回到大约 4500 万年前的新世。

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-新世极热期非常温暖，以至于鳄鱼在北极圈的水域中游来游去。

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，新世-渐新世过渡标志着全球变冷和冰川作用的第一个主要时期。

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，新世后半期也发生了巨大的环境变化。

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

他们在大约 4200 万年前的新世中期到达。