纪录片《恐龙灭绝真相》 第26期 第三纪界线（在线收听）

Between ten million and three million years before the KT boundary,

在第三纪界线前1000万年至300万年间，

the dinosaurs seem to have suffered a dramatic decline.

恐龙的数量开始急剧下降。

One interpretation of the fossil record is that forty percent of dinosaur species went extinct.

化石记录的一个解释是40%的恐龙种类灭绝了。

And so we come up to about one to three million years before the end of the Cretaceous

我们翻看了白垩纪结束前300万年至100万年的地球历史，

and we've got a group that seems to be vulnerable to any kind of extinction events that might be occurring at that time.

我们发现很多脆弱的因素很有可能因为这一时期发生的灭绝事件而遭到毁灭。

So it seems that by three million years before the impact, the dinosaurs were already in trouble.

由此看来在大碰撞发生前300万年，恐龙已经在苟延残喘。

The big question is what happened next?

问题是接下来发生了什么？

Did they stabilise or carry on dwindling?

它们的数量是稳定下来了，还是在继续减少？

What is known is that their environment continued to worsen.

我们所知道的是，它们的环境仍在恶化。

For about half a million years before the KT boundary,

在第三纪界线之前的50万年间，

the world suffered one of its most destructive periods of volcanism ever.

世界经历了最具破坏性的火山活动时期。

Vast areas of land were ridden with eruptions.

大面积的土地被火山灰吞噬。

A million cubic kilometres of lava spewed out in what are known as the Deccan Traps.

在我们所熟悉的德干岩群火山活动中，就喷出了数百万立方公里的熔岩。