Toothed whales, they found, are living on the edge, size-wise.

他们发现就体型而言，齿生活在危险边缘。

Yes, with a fine toothed comb, as usual.

是的，跟往常一样，一字不漏。

Toothed whales thus do seem to have hit some sort of size limit.

因此，齿似乎确实有某种体型上的限制。

Both toothed and baleen whales often hunt by diving deep-prey being more abundant at depth.

齿和须通常都潜入深海捕食，因为深海里的猎物更多。

Broadly, big whales come in two varieties. Toothed whales, such as sperm whales, hunt individual prey.

总的来，鱼有两种。齿，如抹香，捕食单个猎物。

Indeed, some toothed whales and bats emit sound pulses around 200,000 hertz and listen for the reflections.

事实上，一些齿和蝙蝠会发出 20 万赫左右的声脉冲收听反射声。

Light doesn't travel well underwater. So dolphins and other toothed whales navigate like bats, using echolocating clicks.

光在会衰减。所以海豚和其他齿类动物在回声定位，就像蝙蝠一样。

Then you'd use a toothed tool and a smaller hammer for more detailed work in modeling the form.

然后会使一个齿形工具和一个更小的锤子进行更详细的建模工作。

But if he had not walked outside, he would not have been inspired by a kind of toothed grass.

但是如果他不走出家门，他就不能受到一种锯齿状的草的启发。

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

致上讲，这些动物填补了由现代齿目动物海豚和虎所占据的生态龛位。

They're the largest toothed predator on the planet.

它们是地球上最的有齿捕食者。

And with that, they've evolved from being toothed whales.

因此，它们已经从齿进化而来。

But best of all no gap toothed kid in sight to wreck it.

但最重要的是， 看不到有缝隙的孩子来破坏它。

This toothed whale also has a very large brain and complex social life.

这种齿也有非常的脑和复杂的社会生活。

In toothed whales like orcas, grandmothers care for th... by sharing food and knowledge.

在如虎这样的齿群体，祖母们通过分享食物和传授知识来照顾后代。

Its name actually means " toothed turtle." And those teeth looked nothing like pareiasaur teeth.

它的名字实际上意味着“有齿的乌龟”。那些牙齿看起来一点也不像翼龙的牙齿。

The toothed whales include sperm whales, orcas, dolphins, and porpoises.

齿包括抹香、虎、海豚和鼠海豚。

They have very keenly developed echo location sonar sense associated with their brains that is a unique feature of toothed whales.

它们有与脑相关的非常发达的回声定位声纳感觉，那是齿独一无二的特点。

Toothed whales developed echolocation, a way to use sound waves to explore their surroundings.

齿发展出了回声定位能力，这是一种利声波探索周围环境的方法。

For example, it appears from their brain structure that toothed species are unable to smell.

比如，从它们的脑部结构来看，齿是没有嗅觉的。