These are collectively called trace fossils, or more formally, ichnofossils.

这些统称为痕迹化石，或更正式地说，遗迹化石。

But with ichnofossils, it's a lot trickier.

但是对于遗迹化石，它要棘手得多。

But these ichnofossils also tell us something important about what these animals were moving across.

但这些遗迹化石也告诉我们一些关于这些动物迁徙经过的重要信息。

They're also called ichnofossils, and they can give us important clues about things like ancient environments and animal behaviors.

它们也被称为遗迹化石，它们可以为我们提供有关古代环境和动物行为等方面的重要线索。