That's what makes American and Eurasian beavers textbook examples of Ecosystem Engineers.

这就是使美国和欧亚海狸成为生态系统工程师教科书示例的原因。

And fossils show that it lived alongside the modern American beaver.

化石表明它与现代美洲海狸生活在一起。

But the Eurasian and American beavers are still with us, maybe because, unlike Castoroides, they can customize their habitats by building lodges and dams.

但欧亚和美洲海狸仍然与我们同在，也许是因为与河狸不同， 它们可以通过建造小屋和水坝来定制自己的栖息地。

The dam and the generations of North American beavers that maintain it have dramatically transformed the region, creating a pond containing roughly 70,000,000 liters of water.

大坝和维护它的几代北美海狸极大地改变了该地区，创造了一个包含大约 70,000,000 升水的池塘。