They first appeared more than 400 million years ago 它们最早出现在四亿多年前
Seventy million years after the great melt, 大融化7000万年之后
Twenty million years later, life faced one of its greatest challenges... 2000万年后 生命面临又一个巨大的挑战
Forty million years later, and a new era of life has begun, 四千万年后 一个新的生命纪♥元♥开始
And in the tropical shallows 508 million years ago, 在5.08亿年前的热带浅海中
when Earth was stable for 100 million years. 地球保持了一亿年稳定状态
They were to rule for over 150 million years. 它们将统治超过1.5亿年
There are more than ten million species of plant and animals alive today. 如今 超过1000万种动植物 生活在地球上
Two million years ago, and our planet is a very different place. 200万年前 我们的星球与现在完全不同