Cambrian explosion
基础科学

        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.寒武纪生命大爆发hán wǔ jì shēngmìng d......（本文共 417 字）     [阅读本文] >>