cambrian period

基本解释

During the Cambrian period, 500 million years ago, worm-like creatures were evolving into fish-like creatures.
在5亿年前的寒武纪，似蠕虫生物逐渐演化成似鱼生物。
Heand colleagues in Germany and the US studied a database of fossilorganisms that lived on the sea floor from the Cambrian period, about500m years ago.
他和来自德国和美国的同事一起研究了约五亿年前的寒武纪时期生活在海底的生物化石数据库。
Afterward, global large-scale massive volcanic activity in Permian Period generally brought about metamorphism whole middle Cambrian Period volcanic sediment rock in research area.
二叠纪全球性大规模火山活动，致使区内整个中寒武纪的火山沉积岩普遍发生变质。