And Castoroides had incisors that were bigger and curvier than those of living beavers.

Castoroides 的门牙比活海狸的门牙更大、更弯曲。

The last known population of Castoroides died out in the Great Lakes region about 10,000 years ago.

大约 10,000 年前，最后一个已知的 Castoroides 种群在五大湖地区灭绝。

And while experts aren't sure if Castoroides dug burrows, they know it was a swimmer.

虽然专家们不确定 Castoroides 是否挖洞，但他们知道它是游泳者。

Its name was Castoroides and, of course, it's extinct now.

它的名字叫Castoroides，当然，它现在已经灭绝了。

Castoroides stuck around for about a million years.

Castoroides 停留了大约一百万年。

The fossil record shows Castoroides repeatedly invaded the Arctic during those warmer, wetter periods.

化石记录显示， 在那些更温暖、多雨的时期， Castoroides 反复入侵北极。

Luckily, Castoroides could monitor its surroundings without leaving the water.

幸运的是，Castoroides 可以在不离开水的情况下监控周围的环境。

So, Castoroides sounds a lot like modern beavers.

所以，Castoroides 听起来很像现代海狸。

Like its giant ice age colleagues, like the Columbian mammoth, the short-faced bear, and other mega-mammals, Castoroides had some impressive proportions.

就像它在冰河时代的巨型同事，如哥伦比亚猛犸象、短面熊和其他巨型哺乳动物，Castoroides 有一些令人印象深刻的比例。

Like all rodents, Castoroides had big incisors on its upper and lower jaws that never stopped growing.

像所有的啮齿动物一样，Castoroides 的上下颌都有大门牙，并且从未停止生长。