This catastrophic period finished the trilobites off — along with approximately 96% of all marine species.

这段灾性的时期让三叶虫完全消失，所有海洋物种中有近 96% 此劫。

But trilobites left a remarkable record behind.

三叶虫留下了非凡的记录。

Trilobite diversity dwindled, and come about 360 million years ago, only one of the 10 former trilobite orders remained.

三叶虫的多样性减少，到了三亿六千万年前，过去所有的三叶虫目中，只有十目存活下来。

Was it the " Please don't show me another picture of a trilobite" vibe?

是“别再给我看三叶虫照片” 的电吗？

This was the beginning of what would prove to be the trilobite's long demise.

后来证实，这就是三叶虫长灭绝之路的开端。

Trilobites have no direct descendants, but their evolutionary cousins are alive and well.

三叶虫没有直系的后代，它们在演化上的表亲现在仍然活得很好。

With so much time at their disposal, the trilobites proliferated prodigiously.

三叶虫有那么长的支配时间，因此数量激剧增加。

Shelly creatures such as trilobites and brachiopods, of whose ancestors there is little sign in the rocks, are suddenly everywhere.

像三叶虫、腕足动物此般壳类动物的祖先没有在岩层中留下什么，它们的遗却突然间比比皆是。

It's Earth about 500 million years ago, when these creatures, called trilobites, prospered.

这是大约五亿年前的地球，这种生物叫做三叶虫，当时地球是它们的天下。

From about five hundred million years ago, big creatures became much more common, from trilobites to trees to tyrannosaurus rex.

从大约五亿年前开始，大型生物变得更加常见，从三叶虫到树木再到雷克斯霸王龙。

And the first of these new animals to become truly widespread were the trilobites.

这些新动物中第一个 真正广泛传播的动物是三叶虫。

Some creatures like trilobites and brachiopods survived though.

不过，一些生物如三叶虫和腕足动物幸存下来。

Everyone knows what a trilobite looks like, or a theropod track.

每个人都知道三叶虫长什么样，或者兽脚类恐龙的足。

Finding a complete trilobite fossil is still a big moment for a paleontologist.

发现一块完整的三叶虫化石对古生物学家来说，仍是一件大事。”

But the trilobites soon had competition.

是三叶虫很快就有了竞争。

A single-file line of traveling trilobites, all facing the same direction, were caught in a sediment avalanche 480 million years ago.

科学家在4.8亿年前发生的沉淀物雪崩中，发现了一排面朝同一方向迁徙的三叶虫。

Like modern arthropods, trilobites had compound eyes composed of many tiny lenses.

就像现代的节肢动物，三叶虫有由许多小晶体组成的复眼。

And, as the earliest known animals with complex eyes, trilobites had a unique perspective on the ancient world.

三叶虫是目前所知最早具有复眼的动物，它们对古老的世界有着独特的视角。

It is just that we have had a century or so to get used to trilobites. Familiarity, you know, breeds familiarity.

“问题仅仅在于，我们已经花了一个多世纪来习惯于三叶虫。你要知道，熟悉了，就不觉得怪了。”

Many trilobites plowed or burrowed into the seafloor while others swam freely.

许多三叶虫会在海底犁地或挖洞，其他的则自在地游泳。