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古生代大约从五亿年前开始,到一亿八千万年前结束,共经历了大约三亿二千万年漫长的岁月。古生代包括寒武纪、奥陶纪、志留纪、泥盆纪、石炭纪和二迭纪。为了便于理解,我们可以把地球的发展史和人类的历史试作对照,这样,古生代就好比是人类历史上的古代史,而古生代的寒武纪、奥陶纪等每一段,也就相当于古代史的秦、汉各个朝代。在地球发展史的全部过程中,自然界的形形色色,是不断变动的。从地球形成后,地壳一直是在运动的,经过千百万年,就有了明显的变化。地壳的运动虽然复杂多样,
The Paleozoic era began about 500 million years ago and ended 180 million years ago. It has experienced a long period of about 320 million years. Paleozoic includes Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian. For ease of understanding, we can compare the history of the development of the earth with that of human history. In this way, the Paleozoic Era is like the ancient history of human history, and each section of the Paleozoic Cambrian, Ordovician, etc. is equivalent to Ancient history of Qin and Han dynasties. In the entire history of the development of the earth, the diversity of the natural world is constantly changing. After the formation of the earth, the crust has been in motion. After millions of years, there have been significant changes. Although the movement of the earth’s crust is complex,