The amniotic egg is shelled, waterproof, and can be laid on dry land.

羊膜卵有外壳，防水，并且可以孵化在干燥的土地上。

That is, until a breakthrough in evolution changes everything: the amniotic egg.

也就是说，直到一个突破性的进化改变了这一切：羊膜卵。

In fact, the amniotic egg brings the pond with them by enclosing the aquatic environment within its shell.

事实上，羊膜卵用它们的外壳把池塘的水生环境给包裹了起来。