They contended that land animals that began to adapt to aquatic life would soon be neither fowl nor fish, incapable of surviving in either medium.

他们认为，开始适应水生生活的陆地动物很快就会变成既不是鸟也不是鱼，无法在任何一种环境中生存。

The earth was full of these land animals.

地球上充满了所有陆生动物。

But there were no large land animals.

但尚未有大型陆地生物。

Many land animals evolved from aquatic creatures.

许多陆地动物是从水生生物演化而来的。

They are the largest land animals and live up to 70 years.

它们是最大的陆地动物，能活至70岁。