经济学人58:史前爬行动物 蛇颈龙的家族生活

 　　Science and Technology

　　科技

　　Prehistoric¹ reptiles²

　　史前爬行动物

　　A loving mother

　　慈母

　　Family life in plesiosaurs

　　蛇颈龙的家族生活

　　THE Mesozoic land was dominated by dinosaurs³.

　　中生代时期，恐龙统治着陆地。

　　At sea, though, the most abundant reptiles were the ichthyosaurs and plesiosaurs.

　　但是在海里，最繁盛的爬行动物要属鱼龙和蛇颈龙了。

　　Roughly speaking, these animals filled the ecological⁴ niches⁶ now occupied by toothed cetaceans such as dolphins and killer⁷ whales.

　　大致上讲，这些动物填补了由现代齿鲸目动物海豚和虎鲸所占据的生态龛位。

　　Ichthyosaurs, indeed, looked somewhat like dolphins, though plesiosaurs—with their long necks and diamond-shaped paddles—were unlike anything now alive.

　　鱼龙看上去的确有点象海豚，但拥有长颈和菱形鳍状前肢的蛇颈龙却与现存的任何动物不相类似。

　　Ichthyosaurs also resembled cetaceans in another way: unlike most living reptiles, which lay eggs, they gave birth to live young.

　　鱼龙与鲸类动物还有另一点相似之处：大多数现存的爬行动物靠产卵繁殖，而鱼龙是通过怀胎产子的。

　　For years, palaeontologists have wondered if the same was true of plesiosaurs.

　　数年来，古生物学家一直想知道蛇颈龙是否也通过怀胎方式繁殖后代。

　　Now they have found out that it was—but with an interesting twist.

　　如今他们证实了这一点——但却是以一种有趣的方式。

　　Robin⁸ O'Keefe of Marshall University in West Virginia has analysed a plesiosaur fossil found in Kansas in 1987, which palaeontologists had suspected was a pregnant female about 4.7 metres (15 feet) long, but which had not been cleaned up and studied until last year.

　　西弗吉尼亚州马歇尔大学的罗宾·奥基夫对1987年在堪萨斯州发现的蛇颈龙化石进行了分析。此前，古生物学家一直怀疑它是一条身长4.7米（15英寸）雌性怀孕蛇颈龙，但直到去年才将其清理和研究完毕。

　　As he reports in Science, he found an array of tiny bones, apparently⁹ belonging to a small specimen¹⁰ of the same species, in the fossil's abdominal¹¹ cavity (see above; the extra bones are highlighted).

　　奥基夫在《科学》杂志报告中指出，在蛇颈龙化石腹腔内（额外的骨骼被高亮显示）发现了一些小骨骼阵列，它们显然是属于同类物种的小标本。

　　It is unlikely that these were the remains¹² of a meal because the bones are not broken down in the way that would be expected if they were partly digested.

　　这些小骨骼不可能是食物的残渣，因为如果它们是被部份消化的其它动物的骨骼，那么它们的断裂方式应该研究人员所预想的方式相同，但结果却不是。

　　Instead, Dr O'Keefe believes he has discovered evidence that plesiosaurs, too, gave birth to live young.

　　反过来，奥基夫博士相信他已发现了蛇颈龙同样靠胎生繁殖的证据。

　　What is more, all the baby bones come from a single individual, estimated to have been 1.5 metres long.

　　此外，所有幼蛇颈龙的骨骼皆来自于单一的个体，身长估计有1.5米。

　　Ichthyosaurs and other contemporary viviparous species, by contrast, gave birth to multiple offspring.

　　对比之下，鱼龙和其它现代胎生物种可以生育多个后代。

　　The fetus's level of development indicates that it was at most two-thirds mature.

　　从蛇颈龙幼胎的发育水平来看，它最多有三分之二的成熟度。

　　Had it survived to birth it would have been about 1.8 metres in length, and about one and a half times as heavy (relative to parental¹³ weight) as the offspring of other viviparous species of the time.

　　如真能够成功分娩，幼蛇颈龙的身长可能为1.8米左右，体重大约是同时期其它胎生物种后代的1.5倍（相对于父母的重量）。

　　That it was so heavy, and also alone, is of great interest.

　　蛇颈龙幼胎超重且单独的个体引起了古生物学家的极大兴趣。

　　Georges Cuvier, an early palaeontologist, made his reputation by predicting the anatomies¹⁴ of newly discovered fossil species from scant¹⁵ evidence, such as single bones.

　　早期古生物学家乔治·居维叶能在实据不足的情况下（如单一的骨骼）预测出新发现的化石物种的躯干结构，这使他在业界声名显著。

　　He did so by applying to fossils the principles of comparative anatomy¹⁶, asking what light the body shapes of living animals could cast on the shapes of creatures from the past.

　　之所以能做到这点是因为他将对比解剖学的规则应用于化石样本并探寻现存动物的体形对古代动物的体形有什么样的启发借鉴作用。

　　Many modern palaeontologists try to do something similar, except that what they reconstruct is behaviour.

　　许多现代古生物学家除了重现古代动物的行为外，也在尝试做着同样的事情。

　　Dr O'Keefe has performed such an analysis on his find.

　　奥基夫博士已将这种分析应用于他的发现。

　　He starts from a fundamental observation about reproduction: you can go for quantity or quality.

　　他的实验开始于对繁殖现象的基本观察：你能选择数量或质量。

　　Having one child at a time is the ultimate expression of quality.

　　每次只生育一胎是追求质量的最终体现。

　　It implies huge parental investment in the offspring since, if you lose it, you lose everything.

　　它意味着父母在后代身上的巨大投入，一旦失去了这个幼子也就等于失去了一切。

　　Often, too, it implies membership of a social group, within which favours can be traded to spread the load of parenthood.

　　它也常常意味着社会群体的成员身份，在这个社会群体中，幼子关爱可以通过利益交换得到以减轻父母的负担。

　　Most speculatively¹⁷, it might even imply a degree of intelligence—for the most intelligent mammals and birds are generally those that live in groups.

　　从最大程度上猜测，它甚至可能意味着动物的智商程度——生活在群体中的哺乳动物和鸟类通常是最聪明的。

　　All this is a lot to load on a single fossil, of course.

　　当然仅凭这个单一化石，古生物学家未免猜想得太多了。

　　But it would make sense.

　　但它却能够说明问题。

　　It would mean plesiosaurs not only occupied a similar ecological niche⁵ to whales, but behaved like them, too.

　　它将意味着蛇颈龙不仅占据着与鲸鱼相似的生态龛位，其行为方式也与鲸鱼相仿。

1 prehistoric   

adj.（有记载的）历史以前的，史前的，古老的

参考例句：

• They have found prehistoric remains.他们发现了史前遗迹。
• It was rather like an exhibition of prehistoric electronic equipment.这儿倒像是在展览古老的电子设备。

2 reptiles   

n.爬行动物，爬虫( reptile的名词复数 )

参考例句：

• Snakes and crocodiles are both reptiles. 蛇和鳄鱼都是爬行动物。 来自《简明英汉词典》
• Birds, reptiles and insects come from eggs. 鸟类、爬虫及昆虫是卵生的。 来自《现代汉英综合大词典》

3 dinosaurs   

n.恐龙( dinosaur的名词复数 )；守旧落伍的人，过时落后的东西

参考例句：

• The brontosaurus was one of the largest of all dinosaurs. 雷龙是所有恐龙中最大的一种。 来自《简明英汉词典》
• Dinosaurs have been extinct for millions of years. 恐龙绝种已有几百万年了。 来自《简明英汉词典》

4 ecological   

adj.生态的，生态学的

参考例句：

• The region has been declared an ecological disaster zone.这个地区已经宣布为生态灾难区。
• Each animal has its ecological niche.每种动物都有自己的生态位.

5 niche   

n.壁龛；合适的职务(环境、位置等)

参考例句：

• Madeleine placed it carefully in the rocky niche. 玛德琳小心翼翼地把它放在岩石壁龛里。
• The really talented among women would always make their own niche.妇女中真正有才能的人总是各得其所。

6 niches   

壁龛( niche的名词复数 )； 合适的位置[工作等]； （产品的）商机； 生态位（一个生物所占据的生境的最小单位）

参考例句：

• Some larvae extend the galleries to form niches. 许多幼虫将坑道延伸扩大成壁龛。
• In his view differences in adaptation are insufficient to create niches commensurate in number and kind. 按照他的观点，适应的差异不足以在数量上和种类上形成同量的小生境。

7 killer   

n.杀人者，杀人犯，杀手，屠杀者

参考例句：

• Heart attacks have become Britain's No.1 killer disease.心脏病已成为英国的头号致命疾病。
• The bulk of the evidence points to him as her killer.大量证据证明是他杀死她的。

8 robin   

n.知更鸟，红襟鸟

参考例句：

• The robin is the messenger of spring.知更鸟是报春的使者。
• We knew spring was coming as we had seen a robin.我们看见了一只知更鸟，知道春天要到了。

9 apparently   

adv.显然地；表面上，似乎

参考例句：

• An apparently blind alley leads suddenly into an open space.山穷水尽，豁然开朗。
• He was apparently much surprised at the news.他对那个消息显然感到十分惊异。

10 specimen   

n.样本，标本

参考例句：

• You'll need tweezers to hold up the specimen.你要用镊子来夹这标本。
• This specimen is richly variegated in colour.这件标本上有很多颜色。

11 abdominal   

adj.腹（部）的，下腹的；n.腹肌

参考例句：

• The abdominal aorta is normally smaller than the thoracic aorta.腹主动脉一般比胸主动脉小。
• Abdominal tissues sometimes adhere after an operation.手术之后腹部有时会出现粘连。

12 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

13 parental   

adj.父母的；父的；母的

参考例句：

• He encourages parental involvement in the running of school.他鼓励学生家长参与学校的管理。
• Children always revolt against parental disciplines.孩子们总是反抗父母的管束。

14 anatomies   

n.解剖( anatomy的名词复数 )；（详细的）分析；（生物体的）解剖结构；人体

参考例句：

• Man and ape have comparable anatomies. 人类与人猿有类似的构造。 来自互联网

15 scant   

adj.不充分的，不足的；v.减缩，限制，忽略

参考例句：

• Don't scant the butter when you make a cake.做糕饼时不要吝惜奶油。
• Many mothers pay scant attention to their own needs when their children are small.孩子们小的时候，许多母亲都忽视自己的需求。

16 anatomy   

n.解剖学，解剖；功能，结构，组织

参考例句：

• He found out a great deal about the anatomy of animals.在动物解剖学方面，他有过许多发现。
• The hurricane's anatomy was powerful and complex.对飓风的剖析是一项庞大而复杂的工作。

17 speculatively   

adv.思考地，思索地；投机地

参考例句：

• He looked at her speculatively. 他若有所思的看着她。 来自《简明英汉词典》
• She eyed It'speculatively as a cruel smile appeared on her black lips. 她若有所思地审视它，黑色的嘴角浮起一丝残酷的微笑。 来自互联网