The sea lamprey is an ancient jawless fish.

七鳃鳗是一种没有颚的古老鱼类。

It grabs it with its jaws.

它抓住甲虫的颚。

Nanotyrannus did not have the jaw muscles or tooth design for penetrating bone.

矮暴龙的颚肌和牙设计不能咬穿骨头。

The meat was so tough that his jaws hurt from chewing it.

那块肉是如此的坚韧以致他的颚由于嚼它而受伤。

While fish with jaws first appeared in the Silurian, they proliferated in the Devonian.

虽然有颚的鱼最早出现在 志留纪，但它们在泥盆纪大。

So they dissected infected ants and zoomed in on their jaw muscles with electron microscopes.

因此，他们解剖了受感染的蚂蚁，并用电子显微镜放大了它们的颚肌。

The researchers say the acanthothoracid was one of the earliest jawed vertebrates with teeth ever to live.

研究人员表示，acanthothoracid是有史以来最早的有牙的颚脊椎动物之一。

This is because it has to balance out nearly half a ton of head and jaws.

这是因为它需要与半吨重的头颚相平衡。

And Morganucodon still had this old-style jaw joint.

Morganucodon 仍然有这个老式的颚关节。

While orthodontists go through the same training as dentists, they will also need to complete a post-graduate orthodontics course.

虽然牙师要接受与牙医相同的培训，但他们还需要完成研究所的颚学程。

There were a number of short-faced kangaroo species living in Pleistocene Australia, with jaws adapted for grinding up tough leaves.

更新世的澳大利亚生活着许多短脸袋鼠，它们的颚适合磨碎坚硬的树叶。

Somewhere around China, a fish developed jaws, and its descendants drove jawless fishes, sea scorpions and branching plankton to extinction.

在中国的某个地方，一条鱼长出了颚，它的后代使无颚鱼、海蝎子和分支浮游生物灭绝。

And while dire wolves didn't have the jaw strength of their cousins, the borophagines, they could still crack open bones.

虽然恐狼没有它们的表亲食骨狼那样的颚部力，但它们仍然可以咬开骨头。

But remember that a froghopper can accelerate at 550 g's, and the mandibles of the snap-jaw ants pull over 100,000 g's, that's insane.

但是请记住，一只沫蝉可以在 550 个 G 的加速度下加速，而陷阱颚蚁的下颚可以拉动超过 100，000 个 G，这太疯狂了。

But once we got our hands on softer cooked foods, our powerful jaws no longer needed to work as hard and shrank as a result.

但一旦我们掌握了较软的熟食，我们强大的颚不再需要努力工作了也因此萎缩。

The jaws of a T. Rex can leave a bite mark over a meter long. And his 30 centimeter teeth can penetrate deep into flesh.

霸王龙的颚部可以留下一米长的咬痕。而它30厘米长的獠牙可以深深刺入血肉当中。

Reef communities began to collapse, and those new fish with jaws managed to get by as did new life forms on land like plants and insects.

珊瑚礁群落开始崩溃，那些长着颚的新鱼设法生存下来，陆地上的新生命形式如植物和昆虫也是如此。

Fish are the most diverse group of vertebrates with over 30,000 unique species, and much of that diversity is due to the hundreds of unique jaws separating otherwise identical species.

鱼类是脊椎动物中最多样化的群体，有 3 万多个独特的物种，而这种多样性大部分是由于数百个独特的颚部将其他相同的物种分开。

A huge steam shovel opens its jaws, descends into an open amphitheater, licks up five tons at each mouthful, and, swinging sideways over the open cars, neatly deposits its booty.

一个巨大的蒸汽铲张开它的颚，下降到一个开放的圆形剧场，每口舔掉五吨，然后在敞开的车厢上侧身摆动，整齐地存放它的战利品。

We have differences correlated not only with one sex, but with that short period when the reproductive system is active, as in the nuptial plumage of many birds, and in the hooked jaws of the male salmon.

我们发现差异不仅与一种性别有关， 而且与生系统活跃的短暂时期有关，例如许多鸟类的新婚羽毛， 以及雄性鲑鱼的钩状颚。