it would take you about half an hour to reach the time of Christ, and a little over three weeks to get back to the beginnings of human life. 那么你要花大约半个小时才能抵达耶稣的年代，花三个多星期才能返回人类起始的时刻。

But it would take you twenty years to reach the dawn of the Cambrian period. 但是，你要花上20年的时间才能抵达寒武纪初期。

It was, in other words, an extremely long time ago, and the world was a very different place. 换句话说，那是在很久很久以前，当时的世界还是另一个模样。

For one thing, 500-million-plus years ago when the Burgess Shale was formed it wasn't at the top of a mountain but at the foot of one. 首先，当5亿多年前布尔吉斯页岩形成的时候，它不在山顶上，而是在山脚下。

Specifically it was a shallow ocean basin at the bottom of a steep cliff. 具体来说。它是在一座陡峭悬崖脚下的浅海里。

The seas of that time teemed with life, but normally the animals left no record because they were soft-bodied and decayed upon dying. 那个时候的大海里充满了生命，但在通常情况下动物没有留下记录，因为它们是软体动物，一死就腐烂了。

But at Burgess the cliff collapsed, and the creatures below, entombed in a mudslide, 然而，在布尔吉斯，悬崖崩塌下来，下面的生物被泥石流所埋葬，

were pressed like flowers in a book, their features preserved in wondrous detail. 像压在书里的花朵那样被紧紧压住，从而极其详尽地保留了它们的特征。

In annual summer trips from 1910 to 1925 (by which time he was seventy-five years old), Walcott excavated tens of thousands of specimens 从1910-1925年（那时候沃尔科特已经75岁），沃尔科特每年夏天都要出门考察，发掘了成千上万件标本

(Gould says 80,000; the normally unimpeachable fact checkers of National Georgraphic say 60,000), which he brought back to Washington for further study. （古尔德说是8万件，《国家地理杂志》那些通常可靠的事实核对人员说是6万件），将其带回华盛顿作进一步研究。

In both sheer numbers and diversity the collection was unparalleled. 无论在数量上还是在品种上，他的收藏品都是无与伦比的。

Some of the Burgess fossils had shells; many others did not. Some were sighted, others blind. 有的布尔吉斯化石带壳，许多不带。

The variety was enormous, consisting of 140 species by one count. 品种是极其繁多的，有人统计是l40种。