These are very dense bones, not a soft area of the skeleton.

这些是很致密的骨头，并不是骨架里柔软的部分。

In contrast, the sharp bright white areas are where the dense bone material blocks photons from getting through.

与之相反，明亮的白色区域是密度较高的骨质，它们可以阻挡光子透过。

When you exercise regularly, your bones keep up with all that working out by building even more strong dense bone.

如果你经常锻炼的话，你的骨骼会通过构建更强壮、密度更高的骨骼来跟上锻炼的节奏。

And possibly keep our bones dense enough to keep us dancing in our dotage.

并可能使我们的骨骼足够致密，让我们在昏昏欲睡中跳舞。

Those dense bones are part of what gives penguins such a great fossil record!

那些致密的骨头是企鹅如此伟大的化石记录的一部分！

What we see here is the beginning of dense haversian bone.

我们在这里看到的是致密哈佛骨的开始。

We retained a skeletal system of dense, heavy bones that puts a limit on how big we can get before our bones crack under our own weight.

我们保留了一个由致密、沉重的骨骼组成的骨骼系统，这限制了我们在骨骼因自身重量而破裂之前可以长到多大。

We know we begin with calcified cartilage that will form into primary bone and then mature into secondary bone and then eventually develop into something called dense haversian bone.

我们知道我们从钙化软骨开始，它会形成初级骨，然后成熟为次级骨，最后发展成一种叫做致密哈弗斯骨的东西。

It also had other adaptations for life in water, like really dense leg bones, a trait that helps keep mammals like hippos weighted down when they're walking through a river.

它还有其他适合水中生活的适应性，比如非常致密的腿骨， 这种特性有助于让像河马这样的哺乳动物在穿过河流时保持负重。

And we know a lot about their extinct relatives, thanks to their dense bones and preference for living on the coast, because these things made them more likely to be preserved than birds living farther inland.

而且我们对它们已灭绝的亲戚了解很多，这要归功于它们密集的骨骼和对生活在沿海地区的偏爱，因为这些东西使它们比生活在更远内陆的鸟类更有可能得到保存。