我们也许还在津津乐道于恐龙时代或哺乳动物时代，但殊不知第一只动物爬上陆地时，昆虫的时代也已然来临。
We talk about the age of dinosaurs or the age of mammals, but since the first animal climbed onto land, every age has been, by any reasonable measure, the age of insects too.
在恐龙主宰着白天的局势的时代，我们的哺乳动物祖先之所以能够勉强生存下来，可能只是因为他们找到了在夜间谋生的方法。
In the time when the dinosaurs dominated the daytime economy, our mammalian ancestors probably only managed to survive at all because they found ways of scraping a living at night.
始新世时代为古新代的后一时期，它存在于距今五千六百万年以前；据称，就是在这个时期哺乳动物的祖先的进化该是趋于多样化的。
It was during the Eocene, which began 56m years ago, following the Palaeocene, that the ancestors of mammals around today are supposed to have diversified.
现在的问题是--如果遗传科研人员的论断正确无误,那么现存的哺乳动物群就不是起源于始新世时代了.
The trouble is that if the genetics researchers are right, these modern groups did not actually originate in the Eocene.
确实如此,哺乳动物的祖先应该是在距今1亿年—八千五百万年之前出现的,在那个时代恐龙还没有灭绝,并肆无忌惮地啃噬着异类生物.
In fact, their ancestors appear to have emerged between 100m and 85m years ago—a time when the dinosaurs were still alive and chomping.
自始新世（5300-3650万年前）开始，它们便沉睡在化石之中，在那个时代，澳洲板块刚刚与南极板块分离，而现代哺乳动物刚刚开始出现。
The microorganisms had lain dormant since the Eocene epoch, a time when Australia split off from Antarctica and modern mammals first appeared.
冰河时代的北极，灭绝了大量的哺乳动物。
What the Ice Age did was to eradicate the abundant mammalian life in the Northern Hemisphere .
在周口店北京人遗址出土的猿人化石、石制品、哺乳动物化石种类数量之多以及用火遗迹之丰富，都是同时代其它遗址所无法相比的。
For all the ape fossils, stoneware, and fossil of mammals unearthed at the Peking Man Site, other sites of the same age are not its match regarding quantity and miscellany of "fire" remains.
最新的一个代叫做新生代，它是从距今6500万年的时候开始的，这个时期是哺乳动物的时代。
The newest era is called Cenozoic beginning at 65 million years ago. It is the age of Mammals.
对动物来说，大脑的这一部分在哺乳动物还不存在的恐龙时代就已经在进化了。
Download MP3 AudioIn animals, this part of the brain evolved around the time of the dinosaurs before mammals existed.
对动物来说，大脑的这一部分在哺乳动物还不存在的恐龙时代就已经在进化了。
Download MP3 AudioIn animals, this part of the brain evolved around the time of the dinosaurs before mammals existed.
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