Tommotian and Burgess Shale formations give clues about Precambrian evolution.

早间，Tommotian和伯吉斯页岩化石群为前进化提供了线索。

Precambrian animals must therefore have lived at such depths.

因此，前的动物肯定曾生活在这么深的地方。

These findings are not of Precambrian animals themselves, but of their tracks.

发的并不是前的动物本身，而是它们的足迹。

But red in tooth and claw the Precambrian was not—for neither teeth nor claws existed.

但是前时期却不是腥牙血爪，因为那个时候牙齿和爪子都没有出。

The schoolboy turned it in to a paleontologist at the University of Leicester, who identified it at once as Precambrian.

那位小生把化石交给了莱斯特大的一位古生物家。他马上认出那是之前的东西。

On this scale, according to John McPhee in Basin and Range, the distance from the fingertips of one hand to the wrist of the other is Precambrian.

按照这个比例，据约翰·麦克菲在《海洋和山脉》一书中说，一只手的指尖到另一只手的手腕之间的距离代表以前的年代。