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

古新世–新世极热事件时人类并没有濒临灭绝危险，因为我们还不存。

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

尽管白垩纪时期小行星灭绝居统治地位恐龙，但哺乳动物却一直到1000万年后新世才真正兴起繁盛起来。

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

显然，南极物多样性 新世之后受到打击。

But what happened to these Eocene animals?

但是这些新世动物发什么？

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灵长类动物都灭绝。

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

新世时期，气候 开慢慢变冷。

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

植物区地区发现，但它们科显然 要远得多 新世时期广泛存。

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

所以考虑到它大小，它能够支持 新世许多不同态系统。

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

新世南极其他居民可能 也来自南美。

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，即新世中期，气候开变得越来越冷和干燥。

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第一个主要时期。

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

结果，我们世界变暖速度 比新世早。

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

5500 万年前古新世-新世极热期非常温暖，以至于鳄鱼北极圈水域中游来游去。

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

让我们时光倒流到新世，大约4500万年前。

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

我们所知道是，新世晚期和 渐新世早期是全球降温时期。

These were small, nimble carnivores that were adapted to the warm, forested world of the Late Eocene.

这些是适应晚新世温暖森林世界体型较小、动作敏捷食肉动物。

And they show up on all of the continents, except Antarctica, around the same time, in the early Eocene Epoch.

它们新世早期几乎同一时间出现除南极以外所有大陆上。

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

美国，博韦里鳄早新世突然出现，形态完整，准备奔跑。

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新世-新世极热事件或PETM，可能是由多种自然因素造成。

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.

你可以看到亚马逊河形成于新世时期，距今约5600万年前，当时地球要温暖得多，湿润得多。