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

这段灾难性时期让三叶虫完全消失，所有海洋种中有近 96% 也难逃劫。

But trilobites left a remarkable record behind.

但三叶虫留下了非凡。

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

三叶虫多样性减少，到了三亿六千万年前，过去所有三叶虫目中，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” 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开端。

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

三叶虫没有直系后代，但它们在演化上表亲现在仍然活得很好。

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

三叶虫有那么长支配时间，因数量激剧增加。

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

像三叶虫、腕足般壳类祖先没有在岩层中留下什么痕迹，但它们遗迹却突然间比比皆是。

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

这是大约五亿年前地球，这种生叫做三叶虫，当时地球是它们天下。

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.

这些新中第一个 真正广泛传播是三叶虫。

Some creatures like trilobites and brachiopods survived though.

不过，一些生如三叶虫和腕足幸存下来。

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

每个人都知道三叶虫长什么样，或者兽脚类恐龙足迹。

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

发现一块完整三叶虫化石对古生学家来说，仍是一件大事。”

But the trilobites soon had competition.

但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4.8亿年前发生沉淀雪崩中，发现了一排面朝同一方向迁徙三叶虫。

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

就像现代节肢，三叶虫也有由许多小晶体组成复眼。

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

三叶虫也是目前所知最早具有复眼，它们对古老世界有着独特视角。

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，也就不觉得怪了。”

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，其他则自在地游泳。