经济学人167:牙齿的痕迹

 　　Science and technology

　　科学技术

　　Palaeontology

　　古生物学

　　Remember the tooth

　　牙齿的痕迹

　　A link is made in an ancient ecosystem¹

　　古代生态系统中的线索

　　WHO ate whom in the food chains of the past is rarely clear.

　　在古代谁以吃谁为生是不清楚的。

　　Though it is obvious which species were predators³ and which prey⁴,

　　尽管谁是捕食者和谁是猎物是很明显的,

　　the subtle specialisations of feeding habit that allow many types of carnivore to co-exist are rarely preserved in the fossil record.

　　但是专门的微妙的捕食习惯,能让多种食肉动物能够共存的资料很少有保存完好的化石记录。

　　Rarely, but not never.

　　很少有记录不表示没有。

　　That is why the recent discovery of a Jurassic ammonite with a shark's tooth embedded⁵ in its shell has excited palaeontologists.

　　这就是为什么最近发现侏罗纪菊石，连同壳上面的鲨鱼牙齿让古生物学家非常兴奋。

　　The ammonite in question, Orthaspidoceras, a species that thrived 155m years ago,

　　发现的鹦鹉螺是一种叫Orthaspidoceras的生活在一亿五千五百万年前的生物，

　　was part of the collection of an amateur who did not realise the significance of what he had found.

　　化石是由业余爱好者收藏的，他没有意识到他发现的化石的意义。

　　Romain Vullo of the University of Rennes, however,

　　法国雷恩大学的Romain Vullo却明白，

　　did-and he has brought the discovery to the attention of the scientific world in the pages of Naturwissenschaften.

　　而他在《自然科学》杂志上的几页论文吸引了科学界的注意。

　　Ammonites were both predators and prey.

　　鹦鹉螺既是捕食者也是猎物。

　　They occupied a position in the Mesozoic oceans similar to that of modern squid.

　　他们生活在中生代的海洋中，跟现代乌贼相似。

　　Like squid, they were swimming tentacled⁶ molluscs-a group called the cephalopods.

　　跟乌贼一样，鹦鹉螺是游动的有触须的软体动物，属于头足纲动物。

　　Unlike squid, though, they had protective shells.

　　不像乌贼,鹦鹉螺有保护壳。

　　These shells were divided internally into gas-filled chambers⁸.

　　这些保护壳的里面有充满气体的分隔小室。

　　The result had neutral buoyancy, allowing the animal to move by jet propulsion.

　　结果就是鹦鹉螺有浮力,让其像喷气发动机推进一样的运动，这点跟乌贼一样。

　　Modern pearly nautiluses, whose relationship to ammonites is much debated, have a similar arrangement.

　　现代珍珠一样的鹦鹉螺跟远古鹦鹉螺的亲缘关系尽管还有待验证，但是现代鹦鹉螺也有类似的充气推进机制。

　　What ammonites-or, at least, some of them-ate became clear earlier this year when an X-ray showed a small crustacean⁹ in the jaws¹⁰ of a species called Baculites.

　　鹦鹉螺吃什么的问题今年有了答案，x光显示杆鹦鹉螺的咽喉中有小甲壳类动物的痕迹。

　　But what ate ammonites has never been shown in such an unambiguous manner.

　　但是什么吃鹦鹉螺从来没有像现在一样模棱两可。

　　Some ammonite fossils have tooth marks that look as though they were made by huge reptilian¹¹ predators called mosasaurs.

　　一些鹦鹉螺化石上有牙印，看上去仿佛是巨大爬虫类捕食者比如沧龙留下的。

　　Some appear to have been attacked by the beaks¹² of other cephalopods.

　　有些牙印似乎是被其他头足纲攻击的痕迹。

　　And some seem to have been bitten by sharks.

　　有些牙印似乎是鲨鱼留下的。

　　On top of that, coprolites, as palaeontologists politely describe fossil faeces, have turned up with ammonite shells in them.

　　最重要的是,对古生物学家礼貌地描述中的粪化石的研究表明，有些粪便中有鹦鹉螺的壳。

　　Based on comparisons with modern evacua, these are probably from sharks.

　　随着现代技术的发展，研究表明这些粪便来自于鲨鱼。

　　But which sharks?

　　但是哪种鲨鱼吃鹦鹉螺呢?

　　Dr Vullo's ammonite nails one culprit.

　　Vullo博士的化石标本确定了其中的一个罪魁祸首。

　　The tooth belongs to a species called Planohybodus.

　　化石中鹦鹉螺外壳上的牙齿属于一种叫做平弓鲨的物种。

　　And that is a surprise. Those modern sharks that eat shelled animals have robust¹³ teeth for crunching¹⁴ through hard exteriors¹⁵.

　　这是一个惊喜的发现。觅食有壳动物的现代鲨鱼通常长着强壮的牙齿，可以咬穿坚硬的外壳。

　　The teeth of Planohybodus, in contrast, were slender and pointed¹⁶-the sort usually associated with grasping and tearing at flesh.

　　相反，平弓鲨的牙齿,是那种纤细而突出的，一般让人联想到抓住和撕裂肉。

　　In a modern predator², that would indicate the habit of eating fish.

　　在现代掠食者中,拥有这种牙齿意味着习惯吃鱼。

　　That a shark with teeth like this would try to make a meal of an ammonite is, at first sight, odd.

　　长着这样牙齿的鲨鱼,会试图吃掉鹦鹉螺，美餐一顿的理论,乍一看有点古怪。

　　But second thoughts provide a possible explanation.

　　但想一想就有了合理的解释。

　　Ammonites' manoeuvrability would have depended crucially on their buoyancy control.

　　鹦鹉螺的灵活性主要建立在浮力控制上面的。

　　Even a small puncture¹⁷ to the shell, which a pointed tooth would be well able to deliver,

　　即使是壳上的一个小洞,可能就是这样尖牙造成的,就会让水进入壳内,

　　would let the water in and cause that control to vanish.

　　鹦鹉螺从而无法控制浮力。

　　Since ammonites could not withdraw entirely¹⁸ into their shells for self-defence,

　　鹦鹉螺不能完全缩回外壳内自卫,

　　it would then just be a question of dragging the creature out of its chamber⁷ in order to eat it.

　　于是就很可能就会被从外壳中拽出，成了其他生物的美食。

　　And for that, sharp, pointed teeth are ideal.

　　这样说来，锋利的尖牙是完美的武器。

　　1.ancient a.古老的；古代的

　　This is an ancient parable¹⁹.

　　这是一个古老的寓言。

　　2.prey n.牺牲者；被掠食者，猎物

　　She was easy prey for dishonest salesmen.

　　她很容易地让奸商敲了竹杠。

　　3.fossil n.化石；食古不化的人

　　Coal is a fossil fuel.

　　煤是一种矿物燃料。

　　4.jurassic a.侏罗纪的；侏罗系的

　　There are high quality coal resources in Jurassic strata²⁰ of Ordos Basin.

　　鄂尔多斯盆地赋存有侏罗纪优质煤炭资源。

　　5.amateur n.外行；业余爱好者

　　An amateur shouldn't play roulette for high stakes.

　　外行不该下大赌注赌轮盘赌。

1 ecosystem   

n.生态系统

参考例句：

• This destroyed the ecosystem of the island.这样破坏了岛上的生态系统。
• We all have an interest in maintaining the integrity of the ecosystem.维持生态系统的完整是我们共同的利益。

2 predator   

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。

3 predators   

n.食肉动物( predator的名词复数 )；奴役他人者（尤指在财务或性关系方面）

参考例句：

• birds and their earthbound predators 鸟和地面上捕食它们的动物
• The eyes of predators are highly sensitive to the slightest movement. 捕食性动物的眼睛能感觉到最细小的动静。 来自《简明英汉词典》

4 prey   

n.被掠食者，牺牲者，掠食；v.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。

5 embedded   

a.扎牢的

参考例句：

• an operation to remove glass that was embedded in his leg 取出扎入他腿部玻璃的手术
• He has embedded his name in the minds of millions of people. 他的名字铭刻在数百万人民心中。

6 tentacled   

有触角[触手]的

参考例句：

7 chamber   

n.房间，寝室；会议厅；议院；会所

参考例句：

• For many,the dentist's surgery remains a torture chamber.对许多人来说，牙医的治疗室一直是间受刑室。
• The chamber was ablaze with light.会议厅里灯火辉煌。

8 chambers   

n.房间( chamber的名词复数 )；（议会的）议院；卧室；会议厅

参考例句：

• The body will be removed into one of the cold storage chambers. 尸体将被移到一个冷冻间里。 来自《简明英汉词典》
• Mr Chambers's readable book concentrates on the middle passage: the time Ransome spent in Russia. Chambers先生的这本值得一看的书重点在中间：Ransome在俄国的那几年。 来自互联网

9 crustacean   

n.甲壳动物；adj.甲壳纲的

参考例句：

• Seafood is a valuable lobster crustacean section.名贵海珍品龙虾属甲壳科。
• The illustrious Cuvier did not perceive that a barnacle was a crustacean.大名鼎鼎的居维叶也未看出藤壶是一种甲壳动物。

10 jaws   

n.口部；嘴

参考例句：

• The antelope could not escape the crocodile's gaping jaws. 那只羚羊无法从鱷鱼张开的大口中逃脱。
• The scored jaws of a vise help it bite the work. 台钳上有刻痕的虎钳牙帮助它紧咬住工件。

11 reptilian   

adj.（像）爬行动物的；（像）爬虫的；卑躬屈节的；卑鄙的n.两栖动物；卑劣的人

参考例句：

• The chick is ugly and almost reptilian in its appearance. 这只小鸡长得很丑，看起来几乎像个爬行动物。 来自辞典例句
• Being from Orion do Zetas contain DNA from the Reptilian race? 齐塔人是从猎户座而来，DNA来自爬虫族吗？ 来自互联网

12 beaks   

n.鸟嘴( beak的名词复数 )；鹰钩嘴；尖鼻子；掌权者

参考例句：

• Baby cockatoos will have black eyes and soft, almost flexible beaks. 雏鸟凤头鹦鹉黑色的眼睛是柔和的，嘴几乎是灵活的。 来自互联网
• Squid beaks are often found in the stomachs of sperm whales. 经常能在抹香鲸的胃里发现鱿鱼的嘴。 来自互联网

13 robust   

adj.强壮的，强健的，粗野的，需要体力的，浓的

参考例句：

• She is too tall and robust.她个子太高，身体太壮。
• China wants to keep growth robust to reduce poverty and avoid job losses,AP commented.美联社评论道，中国希望保持经济强势增长，以减少贫困和失业状况。

14 crunching   

v.嘎吱嘎吱地咬嚼( crunch的现在分词 )；嘎吱作响；（快速大量地）处理信息；数字捣弄

参考例句：

• The horses were crunching their straw at their manger. 这些马在嘎吱嘎吱地吃槽里的草。 来自《简明英汉词典》
• The dog was crunching a bone. 狗正嘎吱嘎吱地嚼骨头。 来自《简明英汉词典》

15 exteriors   

n.外面( exterior的名词复数 )；外貌；户外景色图

参考例句：

• You mustn't judge people by their exteriors. 你不能以貌取人。 来自《简明英汉词典》
• Some artists only paint exteriors. 有些艺术家只画户外景色。 来自《简明英汉词典》

16 pointed   

adj.尖的，直截了当的

参考例句：

• He gave me a very sharp pointed pencil.他给我一支削得非常尖的铅笔。
• She wished to show Mrs.John Dashwood by this pointed invitation to her brother.她想通过对达茨伍德夫人提出直截了当的邀请向她的哥哥表示出来。

17 puncture   

n.刺孔，穿孔；v.刺穿，刺破

参考例句：

• Failure did not puncture my confidence.失败并没有挫伤我的信心。
• My bicycle had a puncture and needed patching up.我的自行车胎扎了个洞，需要修补。

18 entirely   

ad.全部地，完整地；完全地，彻底地

参考例句：

• The fire was entirely caused by their neglect of duty. 那场火灾完全是由于他们失职而引起的。
• His life was entirely given up to the educational work. 他的一生统统献给了教育工作。

19 parable   

n.寓言，比喻

参考例句：

• This is an ancient parable.这是一个古老的寓言。
• The minister preached a sermon on the parable of the lost sheep.牧师讲道时用了亡羊的比喻。

20 strata   

n.地层（复数）；社会阶层

参考例句：

• The older strata gradually disintegrate.较老的岩层渐渐风化。
• They represent all social strata.他们代表各个社会阶层。