古生代是地质时期的一个时代，从前寒武纪末开始，到中生代初，大约从5.7亿年前到2.25亿年前。
An era of geologic time, from the end of the Precambrian to the beginning of the Mesozoic, or from about 570 to about 225 million years ago.
古生代是地质时期的一个时代，从前寒武纪末开始，到中生代初，大约从5.7亿年前到2.25亿年前。
An era of geologic time, from the end of the Precambrian to the beginning of the Mesozoic, or from about 570 to about 225 million years ago.
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