The samples contained layers of ancient sediment built up over millions of years.

这些样本包含数百万年积累起来的古代沉积物层。

Our best clues can be found in ancient sediments.

我们最好的线索可以在古代沉积物中找到。

Based on that discovery, the researchers are developing new methods that they hope will let them pull even more DNA out of ancient sediments.

基于这一发现，研究人员正在开发新的方法，他们希望能从古代沉积物中提取更多的DNA。