Eventually, their front limbs became flippers and their hind limbs became weak and unnecessary.

最终，它们的前肢变成了鳍状肢，而它们的肢变得虚弱和多余。

And they were almost right. Longer front legs and larger toe pads indeed helped.

他们的想法基本上是对的。前肢更长、趾垫更大确实有帮助。

It affected the young animal's front legs, which became hyperextended.

这种疾病影响了幼崽的前肢，使前肢腕关节过度伸展。

Its powerful arm muscles are composed of 80% fast-twitch fiber, a third more than humans.

它强壮的前肢肌肉中百十是快缩肌纤维，比人类的多三一。

The first was its trio of claws extending from each hand.

第一件是每前肢伸出的三爪子。

All birds have two legs and two arms; but these arms are not like ours.

所有的鸟儿，都有肢，前肢。但是鸟儿的前肢， 跟我们人类的不一样。

We call them wings, and the birds use them for flying.

我们管鸟儿的前肢叫" 翅膀" ，鸟儿是用翅膀来飞翔的。

Powerful forelegs enable it to rip apart a termite hill with ease.

有力的前肢让它们能够轻易地掰开白蚁巢。

Technically, two-toed sloths should be really called two-fingered sloths because the difference is only their front limbs.

从技术上讲，二趾树懒应该被称为二指树懒，因为它们的区别只是前肢。

The shape of the creature's hands and forelimbs suggest it was a skillful and powerful digger, scientists say.

科学家说，这种生物的手和前肢的形状表明它是一种熟练而有力的挖掘者。

Whereas with pterosaurs, with this strategy, you're focusing it into one area and really use it both ways.

所以，翼龙的飞行只会使用到前肢。

What you can see is that large toe pads and strong front legs give some lizards a tighter grip.

你可以看到的是，大的护趾和强壮的前肢使一些蜥蜴抓握更牢。

She has long, strong front legs to help her climb around for food 20 metres up in the canopy.

它的前肢又长又有力，可以帮助它在 20 米高的树冠上四处攀爬觅食。

Led by his super sensitive nose, his long limbs carry him many miles a day in search of carrion.

凭借极度敏感的嗅觉和长长的前肢，短面熊为了寻找腐肉能一天行进数英里。

Although the arms of Albertosaurus were small compared to its overall body size, they were still packed in muscle.

尽管阿尔伯特龙的前肢与体型相比很小，它们也有发达的肌肉。

This meant that the arms were very strong, but their function is somewhat of a mystery.

这说明它的前肢非常强壮，不过其功能有点像迷。

Its small arms are useless in the water, leaving it to rely on its two powerful legs.

它短小的前肢在水中没有用，只能靠条有力的腿。

Like, when primates and squirrels get more practice using their forelimbs to climb trees, that can favor a bigger cerebellum.

比如，当灵长类动物和松鼠用它们的前肢爬树得到更多的练习时，会有更大的小脑。

You see, it is hard for bears to run down hill, because their hind legs are longer than their front ones.

你知道的，熊很难跑下山，因为它们的肢比前肢长得多。

As he rips back, he rips an enormous chunk of flesh from the underside of the arm.

它往拽时，从其前肢下侧拽下来相当大一块肉。