Seventy million years after the great melt, 大融化7000万年之后

264. they are rarely the top predators their towering ancestors once were...
     它们却极少像高大的祖先那般 成为顶级捕食者
265. because in the ancient seas,
     因为在古老的海洋中
266. there was to be a changing of the guard.
     即将发生权力转移
267. Seventy million years after the great melt,
     大融化7000万年之后
268. in a period known as the Devonian,
     进入泥盆纪时期
269. the vertebrates made their move.
     脊椎动物开始行动
270. This is Dunkleosteus...
     这是邓氏鱼

来自《我们星球上的生命 第一季 第二集 Life on Our Planet S01E02 第一前线》第 267 行