plankton had been the catalyst for animal life. 浮游生物是动物生命的催化剂
and Dunkleosteus had reigned for 20 million years. 邓氏鱼已经统治了2000万年
For those who had sought refuge in the deep, 对于那些在深海寻求庇护的生物来说
almost half the planet's ice had melted. 地球上几乎一半的冰已经融化
Within a few more, it had entirely gone. 又过了几千年 冰完全消失
Carbon dioxide levels had bounced back, 二氧化碳水平回升