因此，前寒武纪的动物肯定曾经生活在这么深的地方。
Precambrian animals must therefore have lived at such depths.
发现的并不是前寒武纪的动物本身，而是它们的足迹。
These findings are not of Precambrian animals themselves, but of their tracks.
牙形刺生活在寒武纪的海洋中，可能以某种浮游生物为食，不过没人清楚具体情况。
Conodonts lived in the Cambrian seas, and may have eaten certain types of plankton, but no one knows for sure.
应用推荐