In the late Oligocene, there was also a major split among the simians.

在渐新世晚期，猿类之间也发生了重大 分裂。

The oligocene was a time of changing environments  and the forests proailurus originated gradually turned into grasslands.

渐新世是一个环境变化的时期，起源的森林逐渐变成了草原。

And, during the early Oligocene, wooded grasslands that thrived in lower CO2 levels and a cooler climate also expanded.

而且，在渐新世早期，在较低的二氧化碳水平和较凉爽的气候中茁壮成长的树木繁茂的草原也在扩大。

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-渐新世过渡标志着全球变冷和冰川作用的第一个主要时期。

For the most part, the rest of the Miocene continued the trends that began in the Oligocene.

在大多数情况下，中新世的其余部分 延续了渐新世开始的趋势。

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，始新世晚期和 渐新世早期是全球降温的时期。

Then, in the cooler, drier climate of the Oligocene, a new habitat appeared: grassland.

然后，在渐新世凉爽干燥的气候中 ，出现了一个新的栖息地：草原。

These were species like Pseudobassaris, a ground-dwelling badger-like creature whose fossils have been found in Oligocene deposits in France.

这些是像 Pseudobassaris 这样的物种，这是一种地栖的獾状生物， 其化石已在法国的渐新世矿床中发现。

As their prey adapted to life in the new grasslands of the Oligocene, the mustelids did too.

当它们的猎物适应了渐新世新草原的生活时，鼬科动物也适应了。

During the Oligocene and Miocene Epochs, it made huge, spiraled dens in the earth.

在渐新世和中新世时期，它在地球上形成了巨大的螺旋状洞穴。

Regardless of where they lived, the early paleomustelids were about to witness a big global change that took place in the Oligocene.

无论生活在何处，早期的古鼬科动物都即将见证发生在渐新世的全球性大变化。

So, Mesohippus and Miohippus roamed the continent together at the start of the Oligocene.

因此，中马和中马在渐新世初期一起在大陆漫游。

And it only approached the Asian Sunda continental shelf in the west around 20 to 25 million years ago in the late Oligocene or early Miocene epoch.

而且，它只有在大约 2,000 万到 2,500 万年前的渐新世晚期或中新世早期和在西面的亚洲巽他古大陆接壤。

They are part of another important beaver subgroup, one that evolved by the end of the Oligocene.

它们是另一个重要的海狸亚群的一部分，该亚群在渐新世末期进化而来。

As the Eocene transitioned to the Oligocene, the climate cooled.

随着始新世过渡到渐新世，气候变冷。

It made its debut in the early Oligocene and was about the size of a fox.

它在渐新世早期首次亮相，大约有一只狐狸那么大。

By the mid-Oligocene, the smaller Mesohippus had disappeared.

到渐新世中期，体型较小的中马已经消失。

And the cause might have been the rise of marine mammals, especially new groups of toothed whales that happened in the Oligocene Epoch.

原因可能是海洋哺乳动物的兴起，尤其是渐新世时期出现的新齿鲸群。

And by the Early Oligocene Epoch, fossils from China tell us that beavers were quick to establish themselves in Eurasia.

到渐新世早期，来自中国的化石告诉我们，海狸很快就在欧亚大陆安家落户。

Around the start of the Oligocene Epoch, about 33 million years ago, Earth began to cool, and glaciers in Antarctica started growing faster.

在大约 3300 万年前的渐新世初期，地球开始变冷，南极洲的冰川开始增长得更快。