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当前位置:首页 -> 11级英语阅读 - > 250万年鳄鱼祖先化石表明鳄鱼也胎生
250万年鳄鱼祖先化石表明鳄鱼也胎生
添加时间:2017-02-28 17:11:23 浏览次数: 作者:未知
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  • It was thought to only lay eggs but experts have provided the first ever evidence that an ancient ancestor of the crocodile also had live births.A remarkable1 250 million-year-old fossil has been discovered which contains an embryo2 inside the mother.

    鳄鱼一般被认为是只下蛋的,但专家提供了一个远古鳄鱼胎生的证据-----一个两亿五千万年前含有胚胎的母鳄鱼化石被发现。

    The new fossil is from a distant ancestor of the crocodile that flourished in shallow seas of South China in the Middle Triassic.Live birth is well known in mammals where the mother has a placenta to nourish the developing embryo.It is also very common among lizards3 and snakes where the babies sometimes 'hatch' inside their mother and emerge without a shelled egg.

    新化石来自一个生活在三迭纪华南浅海的远古鳄鱼。胎生在哺乳动物中是众所周知的,哺乳动物母亲具有滋养胚胎发育的胎盘。蜥蜴和蛇中也非常普遍有时婴儿在他们的母亲体内“孵化”而没有壳蛋的出现(蝮蛇等,也叫卵胎生)。

    Until recently the third major group of living land vertebrates the crocodiles and birds only laid eggs.

    直到最近,作为第三种主要的陆生脊椎动物:鳄鱼和鸟类都被认为是只下蛋的。

    Researchers from Hefei University of Technology in China discovered the new fossil of an unusual long-necked animal called Dinocephalosaurus - a creature that flourished in shallow seas of South China in the Middle Triassic.

    来自中国合肥工业大学的研究者们发现了新的化石——一种罕见的叫做“东方恐头龙”的长颈动物,这一生物在三叠纪中期时在华南浅海曾经大量繁衍。

    An embryo was found inside the rib4 cage of the mother and facing forwards.

    在恐头龙妈妈的胸腔里面发现了一个面朝前方的胚胎。

    This suggests that the animal was not eaten - as swallowed animals generally face backwards5 because the predator6 swallows its prey7 head-first to help it go down its throat.

    这表示这个动物可能不是被捕食的。通常被吃下的动物是面朝后的,因为食肉动物为了顺利吞咽那些被捕食的动物,经常先从脑袋吞起。

     11级    英文科普 
     单词标签: remarkable  embryo  lizards  rib  backwards  predator  prey 


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    1 remarkable [rɪˈmɑ:kəbl] 8Vbx6   第7级
    adj.显著的,异常的,非凡的,值得注意的
    参考例句:
    • She has made remarkable headway in her writing skills. 她在写作技巧方面有了长足进步。
    • These cars are remarkable for the quietness of their engines. 这些汽车因发动机没有噪音而不同凡响。
    2 embryo [ˈembriəʊ] upAxt   第8级
    n.胚胎,萌芽的事物
    参考例句:
    • They are engaging in an embryo research. 他们正在进行一项胚胎研究。
    • The project was barely in embryo. 该计划只是个雏形。
    3 lizards [ˈlɪzədz] 9e3fa64f20794483b9c33d06297dcbfb   第8级
    n.蜥蜴( lizard的名词复数 )
    参考例句:
    • Nothing lives in Pompeii except crickets and beetles and lizards. 在庞培城里除了蟋蟀、甲壳虫和蜥蜴外,没有别的生物。 来自辞典例句
    • Can lizards reproduce their tails? 蜥蜴的尾巴断了以后能再生吗? 来自辞典例句
    4 rib [rɪb] 6Xgxu   第7级
    n.肋骨,肋状物
    参考例句:
    • He broke a rib when he fell off his horse. 他从马上摔下来折断了一根肋骨。
    • He has broken a rib and the doctor has strapped it up. 他断了一根肋骨,医生已包扎好了。
    5 backwards [ˈbækwədz] BP9ya   第8级
    adv.往回地,向原处,倒,相反,前后倒置地
    参考例句:
    • He turned on the light and began to pace backwards and forwards. 他打开电灯并开始走来走去。
    • All the girls fell over backwards to get the party ready. 姑娘们迫不及待地为聚会做准备。
    6 predator [ˈpredətə(r)] 11vza   第9级
    n.捕食其它动物的动物;捕食者
    参考例句:
    • The final part of this chapter was devoted to a brief summary of predator species. 本章最后部分简要总结了食肉动物。
    • Komodo dragon is the largest living lizard and a fearsome predator. 科摩多龙是目前存在的最大蜥蜴,它是一种令人恐惧的捕食性动物。
    7 prey [preɪ] g1czH   第7级
    n.被掠食者,牺牲者,掠食;vi.捕食,掠夺,折磨
    参考例句:
    • Stronger animals prey on weaker ones. 弱肉强食。
    • The lion was hunting for its prey. 狮子在寻找猎物。

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