The skull also lacks a blowhole, another cetacean adaptation for diving.

颅骨上缺少一个可以进行适应性潜水的排气孔。

At new risk are cetaceans like the North Atlantic right whales.

对北大西洋露脊鲸这类鲸目科动物来讲同样面临着这种新的致命危险。

Very exciting discoveries have finally allowed scientists to reconstruct the most likely origins of cetaceans.

这项非常令人兴奋的发现终于使科学家们能够重建鲸目动物最有可能的起源。

I'm from Mystic Aquarium in Mystic, Connecticut. I'm a trainer of cetaceans and pinnipeds there.

我来自康涅狄格州的神秘水族馆。我是一名鲸目动物和鳍足类动物教练。

It is one of the earliest whales and the oldest cetacean discovered that had functional legs.

它是最早发现的鲸目动物之一，也是最早发现的有腿的鲸目动物。

Roughly speaking, these animals filled the ecological niches now occupied by toothed cetaceans such as dolphins and killer whales.

大致上讲，这些动物填补了由现代齿鲸目动物海豚和虎鲸所占据的生态龛位。

Our frigate drew nearer to the cetacean. I examined it with a completely open mind.

我们的战舰埃近了这个鲸鱼类动物。

What can be this cetacean, which neither Cuvier nor Blumenbach knew anything about?

居维叶和布鲁门巴赫都不知道的这只鲸类动物到底是什么？

Every cetacean known to man is endangered.

任何人类已知的鲸类动物。

Ichthyosaurs also resembled cetaceans in another way: unlike most living reptiles, which lay eggs, they gave birth to live young.

大多数现存的爬行动物靠产卵繁殖，而鱼龙是通过怀胎产子的。