知識貝殼
知識貝殼
Definition: The Cambrian explosion or Cambrian radiation was the relatively rapidappearance,over a period of many million years,of most major groups of complex animalsaround 530 million years ago,as found in the fossil record.寒武紀(jì)生命大爆發(fā)hán wǔ jì shēngmìng d ......（本文共 417 字 ） [閱讀本文] >>