[转载]中国发.翼龙中变 现了翼龙妈妈

Mama Pterosaur Discovered in China

在中国发现的达尔文翼龙的化石（见上图）和它的卵永久地保存了下来，该翼龙可能曾经对雄性达尔文翼龙深感动心，由于雄性展示出了高大的冠子（见下图）。
The pregnant pterosaur was just trying to make it home in time to lay her egg. But when a sudden storm assaulted the 3-foot-long flying reptilian, the wind short of money her wing, sending her spiraling down into a lake. As the mud sucked her under, the pressure expelled her egg, which fossilized beside her as the mud turned to rock. 为了及时迎接产卵，一只怀孕的翼龙正在努力地赶往家中。然而天有不测风云，一场暴风雨袭击了这只会飞翔的、身长三英尺的爬行动物，大风刮折了它的翅膀，使它盘旋下落入一个湖泊中，盖在它身上的淤泥越来越厚，压力把它体内的卵挤压出来，随着淤泥变成了岩石，它的卵也在它的身旁变为化石。
"It was a tragedy," says paleontologist David Unwin of the University of Leicester in the United Kingdom, whose rectalysis of the fossil was published today in Science. He and colleagues say the find could answer longstanding questions about differences between pterosaur sexes. “这是一场悲剧，”英国莱斯特大学的古生物学家大卫·昂温说，他对该化石进行了分析，将结果发表在今天出版的《科学》杂志上。昂温及同事说，该发现可以解答由来已久的、有关翼龙性别差异的问题。
Researchers began studying the fossil after a farmer in the Liaoning Province of China sold it to the Zhejiang Museum of Natural History in 2009. There, Junchang Lüof the Chinese Academy of Geological Sciences dated the fossil as 160 million years old and identified it as Darwinopterus, a mid-Jurassic pterosaur which Lü, Unwin, and others had first identified in 2009. Affectionately known as Mrs. T (a misspelling of pterosaur), the new fossil is a rare example among extinct animals of a virtually complete skeleton with an egg. 自从2009年中国辽宁省的一个农民将这块化石卖给浙江省自然历史博物馆之后，研究人员就开始研究这块化石。中国地质科学院的吕君昌确定该化石已有一亿六千万年，并确定化石中的动物为达尔文翼龙，这是生活在侏罗纪中期的一种翼龙，这种翼龙最初是由吕君昌、昂温级其他研究人员在2009年发现的。这块新化石中的翼龙被亲切地称为T夫人（T从对“pterosaur翼龙”的错误拼写而来），有着近乎完整的骨架，还带有一枚卵，是灭绝动物中的一个珍贵的标本。
It also represents only the fourth pterosaur egg ever discovered. Even more unusual, Mrs. T's egg appears to have just been laid. The researchers say that the eggshell appears crumpled and soft like a reptile's, indicating that pterosaurs buried their eggs to soak up nutrients from the ground and left the hatchlings to fend for themselves, rather than caring for them as a bird would. 这枚卵也是所发现的第四枚恐龙卵。更不同寻常的是，T夫人的卵好像是刚刚产下的。研究人员称：卵壳上带有褶皱，而且柔软，就像爬行动物的卵，这表明为了吸收大地的营养，翼龙将它们的卵埋起来，然后让新孵出的小翼龙进行自我照料，而不像鸟类那样照料小鸟。
If the structure is indeed Mrs. T's egg, there can be no doubt that the fossil is a female, says Unwin. And that would mean that features such as her large pelvis and lack of a bony headcrest may be defining characteristics of Darwinopterus females. It also means that headcrests, which Unwin believes were most likely used by males to intimidate rivals or woo a mate, likely varied in size and boniness between individuals and among the approximately 130 species of pterosaur currently classified. 昂温说，如果这个构造的确是T夫人的卵，那么毫无疑问这块化石中的翼龙就是雌性的。这意味着，像该翼龙身上的宽大骨盆、头上没有骨质冠子等情况可能是雌性达尔文翼龙明确的特征。昂温认为：这还意味着冠子很可能是雄性翼龙用来威胁对手，或者用来向雌性求爱的；在个体与个体之间，在目前已经进行了分类的近130种翼龙中，冠子的大小及冠子骨骼的高低很可能会有所不同。
Paleontologist Kevin Padian of the University of California, Berkeley, is skeptical about using headcrests to define pterosaur gender. Mrs. T may lack a bony headcrest not because she was female, but because she was young, he says. "Anything horny, antlery, or feathery gets more that way as an animal gets older," says Padian, adding that too little is known about the size of mature pterosaurs to be able to tell whether the fossil is full-grown. 对于利用冠子能否确定翼龙的性别，加州大学伯克利分校的古生物学家凯文·帕蒂恩表示怀疑。帕蒂恩称，T夫人没有骨质冠子，或许不是由于它是雌性，而是由于它还年轻。“在那个部位，任何角质的或羽毛类的东西都会随着动物年龄增长而变大或变多，”帕蒂恩说。接着他又说道，研究人员对于成熟翼龙的大小知之甚少，还不能断定这块化石中的翼龙是否已经发育成熟。
He's also not convinced that the round structure found with the pterosaur is an egg. Padian says it's far too large to be an egg as it would take up much of the pterosaur's body cavity. Plus, he says, reptiles lay dozens of eggs at a time. 帕蒂恩也不能确信翼龙旁边那个圆形构造就是一枚卵。他说，那个构造太大了，不会是一枚卵，由于如果是一枚卵的话，它会占据翼龙的大部分体腔，此外，爬行动物一次产卵可达几十枚。
Still, paleontologist Mark Witton of the University of Portsmouth in the United Kingdom, says the discovery sheds light on these enigmatic animals. Unlike dinosaurs, whose ancestral features are preserved in birds, pterosaurs were an evolutionary dead end. "They're intriguing—and confusing—animals to study," he says. "When Darwinopterus was first discovered, it bridged the gap between two anatomically distinct pterosaur groups. It will be interesting to see what else this animal reveals." 尽管如此，英国朴茨茅斯大学的古生物学家马克·威顿说，该发现清晰地展示了这些神秘的动物。普通恐龙的遗传特征在鸟类中有所保留，而翼龙则不同，它们的进化到了尽头。“它们是很有趣而又让人费解的动物，值得研究，”威顿说，“自从最初发现达尔文翼龙的时候起，这种翼龙就在两类截然不同的翼龙之间架起了一座桥梁，弥合了两者在解剖学上的差距。看一看这个动物还会揭破出什么其他情况，那将是很有趣的事情。”
译自：美国《科学》杂志网站（20 January 2011, 2:37 PM）
原著：Sara Reardon