【Introduction】

  

【Main Contents】


The Cambrian is a geologic period that began around 542 million years ago (see below) and ended about 490 million years ago. The Cambrian Period is the earliest period in whose rocks are found numerous large, distinctly-fossiliz- able multicellular organisms more complex than sponges or medusoids. During this time, roughly fifty separate major groups of organisms or"phyla"(including almost all the basic body plans of modern animals) emerged suddenly, in most cases without evident precursors. This radiation of animal phyla is referred to as the Cambrian explosion. The dawn of animal world had came through wenan radicalization, yidikala radiation, meishucun radiation, and maotianshan radiation one by one. This process is Punctuated Equilib- rium that different from after 500 million years.
In this book, 547 color photos were embodied.