Smaller-sized relatives in the genus Wakaleo, or 'little lions, ' first appeared in the Late Oligocene epoch, around 25 million years ago.

Wakaleo 属中体型较小的近亲首次出现于渐新世晚期，距今约 2500 万年前。

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。

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。

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。

Only three species of these skin-shelled turtles are found in the Oligocene Epoch, two in the Miocene, and just one in the Pliocene.

在渐新世只发现了三种这种皮壳龟，在中新世发现了两种， 在上新世发现了一种。

And by the start of the Oligocene epoch, about 35 million years ago, giants like Paraceratherium measured a whopping 4 to 6 meters tall at the shoulder and around 7.5 meters long.

在大约 3500 万年前的渐新世初期，像 Paraceratherium 这样的巨人的肩高高达 4 到 6 米，长约 7.5 米。

And they also include Oaxacagale from southern Mexico, dated to at least the Early Oligocene Epoch about 30 million years ago, and they may go as far back as 40 million years ago.

它们还包括来自墨西哥南部的 Oaxacagale，其年代至少可以追溯到大约 3000 万年前的早渐新世时期，它们可能追溯到 4000 万年前。

It weighed a mere 15 tons, and stood about 5 meters high at the shoulder, roaming Eurasia from Romania to China, at the end of the Oligocene Epoch, long after the non-avian dinosaurs disappeared.

它仅重 15 吨，肩高约 5 米，在非鸟类恐龙消失很久之后的渐新世末期，从罗马尼亚漫游欧亚大陆到中国。