They are the first footprint evidence that some ancient ancestors of modern crocodiles walked on two legs.

它们是现代鳄鱼的一些远古祖先用两条腿行走的第一个足迹证据。

Now, it can be pretty easy to figure out what made a modern trace - because we can actually observe it happening - like, watching a crocodile walk through mud, leaving its footprints behind.

现在，很容易弄清楚是什么形成了现代足迹——因为我们可以实际观察到它的发生——就像看着鳄鱼穿过泥泞，留下脚印一样。