Bovids, equids and, in particular, canids, were put to work by H.sapiens; felids always took a slightly different view of the matter, but were indulged for their rodent-catching talents.

牛科动物、马科动物，尤其犬科动物，都由智人分工的；猫科动物略有不同，但受宠的原因主要捕捉啮齿类生物的天性。

If anything, dogs resemble juvenile rather than fully adult canids, a sort of arrested development which accounts for the way they remain dependent on their human owners throughout their lives.

如果说狗与犬科动物确有相似性，那么也只像未成年而非成年犬科动物。这种类似发育停滞的现象可以解释狗为何一生都如此依 赖主人。

Other species of canids — dogs, wolves — hunt in packs, but her life is a lonely one.

其他的犬科动物——狗、狼，都狩猎，但鬃狼却作战。

Now, some experts think the earliest canid was a small, weasel-like creature called Prohesperocyon, which first appeared about 36 million years ago in southern Texas.

现在， 一些专家认为最早的犬科动物一种类似鼬的小型生物，名为原黄昏犬（Prohesperocyon），它大约在3600万年前首次出现在美国得克萨斯州南部。

So, the dingo is a unique Australian animal, a wild canid and an apex predator essential for the health of Australia's ecosystem.

因此，澳洲野狗澳大利亚独有的动物、野生犬科动物和对澳大利亚生态系统健康至关重要的顶级捕食者。

But other groups, like canids, bears, and whales, were fully fledged.

但其他，如犬科动物、熊和 鲸鱼，已经完全成熟。

Their scientific name, vulpes  lagopus means hare-footed fox, as this furry pad adaptation  is unique among canids.

它们的学名 vulpes lagopus 意思兔足狐，因为这种毛茸茸的垫子适应性在犬科动物中独一无二的。

Not everyone's convinced that Prohesperocyon was a canid, though.

并非所有人都认为“前黄昏犬”犬科动物。

So do certain canids and crows.

某些犬科动物和乌鸦也如此。

Like other truly wild canids, it displays unique behaviors.

与其他真正野生的犬科动物一样，它表现出独特的行为。

These canids are relatively small, at about  60 cm in length and weighing just over 3kg.

这些犬科动物相对较小，长约 60 厘米，重量仅超过 3 公斤。

Today there are 34 species of canids, from the leggy maned wolf to the big-eared fennec fox.

如今有34种犬科动物，从长腿的鬃狼到大耳的芬NE克狐。

But in canids, they're especially big, and it's thought that these extra large spaces help dogs and wolves hear low-frequency sounds.

但在犬科动物中， 它们特别大，人们认为这些超大空间有助于狗和狼听到低频声音。

So while the canines went on with their own set of prey and long-distance hunting strategies, the bone-crushers, once the most dominant of the canids, found themselves struggling for survival.

因此，在犬科动物继续追求自己的猎物和长途狩猎策略的同时，曾经最为强大的碎骨犬亚科却发现自己在生存斗争中举步维艰。

So two out of the three canid subfamilies are dead and gone.

所以三个犬科亚科中有两个已经灭绝了。

Either way, every canid — from the giant bone-crushers to the pup that's probably watching this with you right now — all share some key traits.

无论哪种情况，每一种犬科动物——从巨大的碎骨者到此刻可能正和你一起观看的小狗——都具有一些关键特征。

Now, tens of millions of years ago, some ancestral canid, whether it was Prohesperocyon or someone else, was the predecessor to the first of the three great subfamilies of canids.

现在， 数千万年前， 一些祖先犬科动物，无论原黄昏犬（Prohesperocyon）还其他物种，都犬科三大主要亚科的第一个前身。

One species in this genus—Epicyon haydeni—was the biggest of the big, thought to be the largest canid of all time.

该属中的一种——伊皮西翁犬海登氏种——最大的巨型犬，被认为史上最大的犬科动物。

The only important thing that Epicyon has in common with your golden retriever or whatever is that they're both canids.

伊皮西翁犬与你的金毛寻回犬或其他犬类唯一共同的重要之处在于它们都属于犬科。

But around 30 million years ago, a new subfamily of canids appeared: Caninae, or canines, the true dogs.

但大约 3000 万年前， 出现了一个新的犬科动物亚科：Caninae，或犬科动物， 真正的狗。