背诵为王第四册第40课 Feathered Dinosaur
2009-05-28来源:和谐英语
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Two summers ago, a farmer in northeast China was digging in a dried-up lake. He dug up some strange-looking fossilized bones. He wondered: Could these be the remains of ancient dragons?
Not quite. The bones actually belonged to an ancient meat-eating dinosaur named Sinosauropteryx prima. The creature, which was close to the size of a large chicken, lived about 120 million years ago.
Size may not have been the only thing this dinosaur had in common with the chicken. Scientists announced that Sinosauropteryx might have had tiny feathers!
Many scientists had wondered whether some dinosaurs had any feathers. But feathers are so fragile that they usually rot away without a trace. Luckily, the Sinosauropteryx fossils showed a lot of detail. "I had been skeptical of the claim that the dinosaur had feathers," says Canadian scientist Phil Currie. "Boy, was I impressed!"
Not everyone is convinced. Some bird's experts suggest that the feather-like structures may be bits and pieces of scales.
Whatever they are, they are not the right size and shape for flying. They may have been used to keep the dinosaur warm or help it attract a mate.
When and why feathers first appeared on the earth is just one puzzle scientists hope to solve by studying the area where the fossils were found. "These beds date to a time when modern mammals, flowering plants, and birds were invented," says Alan Brush, bird expert at the University of Connecticut. "The discovery of this site is just as important as going to Mars."
dinosaur 恐龙
fossilize 使成化石
prima 第一的, 主要的
有羽毛的恐龙
两年前,中国东北的一位农民在一个已经干涸的湖床挖地时,挖出了一些样子很奇怪的化石。他想,这是不是古代龙的遗骸呢?
并非如此。这些骨头其实是古代一种名叫中华鸟龙的肉食恐龙的化石。中华鸟龙,大小接近一只体型稍大的鸡,生活在距今一亿两千万年前。
身体大小可能不是中华鸟龙和鸡唯一的相似之处。科学家们宣称中华鸟龙可能长有微小的羽毛。
很多科学家一直在思考恐龙是否长有羽毛。但是羽毛很脆弱,通常很快就腐烂掉,不会留下痕迹。幸运的是,中华鸟龙化石显示了很多这方面的细节。“我过去一直怀疑恐龙长有羽毛这种说法”,加拿大科学家费尔•贾利说,“哦,这真是令人难忘。”
并不是所有人都相信这一点。有些鸟类专家说这些羽毛状的结构可能是鳞的碎片。不管它们是什么,都不具有适于飞行的尺寸和形状,可能是用来保暖或者增加吸引配偶的魅力。
科学家们通过研究发现这些化石的地方,希望能找到羽毛最早什么时候和为什么在地球上出现这个谜题的答案。“这些湖床可以追溯到现代哺乳动物、有花植物和鸟类最早出现的年代”,康涅狄格大学的鸟类专家艾伦•布鲁斯说,“发现这个遗址的重要性相当于探索火星。”
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