- In time, others would follow.
随着时间的推移 其他生物也会跟随而来 - But more than half a billion years ago,
但是五亿多年前 - the open ocean belonged to them.
广阔的海洋属于它们 - For those still stuck on the seabed,
对于那些仍困于海床上的生物来说 - escaping predation required a different approach.
逃避被捕食需要一种不同的方式 - This curious creature
这种奇怪的生物 - is a trilobite.
是三叶虫