- Yet, in the shallows,
但是在浅海中 - 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 - because in the ancient seas,
因为在古老的海洋中 - there was to be a changing of the guard.
即将发生权力转移 - Seventy million years after the great melt,
大融化7000万年之后 - in a period known as the Devonian,
进入泥盆纪时期 - the vertebrates made their move.
脊椎动物开始行动