Tommotian and Burgess Shale formations give clues about Precambrian evolution.

早间，Tommotian和伯吉斯页岩化石群为前寒武纪进化提供了线索。

Precambrian animals must therefore have lived at such depths.

因此，前寒武纪动物肯定曾生活在这么深。

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

发现并不是寒武纪前动物本身，而是它们足迹。

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

是前寒武纪时期却不是腥牙血爪，因为那个时候牙齿和爪子都没有出现。

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

那位小学生把化石交给了莱斯特大学一位古生物学家。他马上认出那是寒武纪之前东西。

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，一只手指尖到另一只手手腕之间距离代表寒武纪以前年代。

Nowadays, and speaking very generally, geological time is divided first into four great chunks known as eras, Precambrian, Paleozoic, from the Greek meaning old life, Mesozoic, middle life, and Cenozoic, recent life.

现在, 一般来说, 质时间首先分为四个大块, 称为时代, 前寒武纪, 古生代, 来自希腊语, 意思是旧生活, 中生代, 中生代和新生代, 最近生活。