Hundreds of millions of years after Anthracosaurus, 石炭鲵出现之后几亿年
The evolution from fin to limb took millions of years. 从鳍到肢的进化用了数百万年
that has remained almost the same for hundreds of millions of years. 已经保持了数亿年 几乎不变
Its design has been fine-tuned over millions of years. 它的设计经过了数百万年的精心调整
which they ruled undisturbed for the next 40 million years. 在之后的4000万年 不受滋扰地统治着陆地
where life had thrived for more than a billion years, 生命已在这里繁荣超过10亿年
Millions of years before the age of dinosaurs... 在恐龙时代之前数百万年