VOA慢速英语--研究表明恐龙可能是从非常小的生物衍变来的

A new study adds to growing evidence that dinosaurs² may have developed from very small animals.

Scientists have studied the fossil of a small animal, called Kongonaphon kely, which is believed to be an ancestor of the dinosaurs. The name given the reptile³ means "tiny bug⁴ slayer," or very small killer⁵ of insects.

The four-legged animal is believed to have been just 10 centimeters tall and about 40 centimeters long. Researchers say it lived about 237 million years ago in what is now Madagascar.

Scientists described examinations of the fossil in a recent study published in Proceedings⁶ of the National Academy of Sciences.

The researchers believe the animal came before dinosaurs, which developed in the Mesozoic Era. It ended about 66 million years ago. The study notes that much remains⁷ unknown about the history of dinosaurs and their winged relatives, pterosaurs.

Scientist Christian⁸ Kammerer of the North Carolina Museum of Natural Sciences, led the study. Kammerer told Reuters news agency that based on the body size suggested by the fossil, "we argue that dinosaurs and pterosaurs evolved from a miniaturized ancestor."

John Flynn, of New York's American Museum of Natural History, was a co-writer of the study. He said earlier studies have also supported the argument. "Evolution of gigantism from tiny ancestors is not uncommon⁹ in the fossil record," Flynn said.

The scientists said the Kongonaphon's teeth showed signs of use in a way that suggested the small reptile ate insects.

The team examining the fossil also found evidence of "fuzzy skin coverings," including feathers. The researchers said the feathers may have developed in the small-bodied creature to help control body temperature. This would have been especially important in the extreme climate of the early part of the Mesozoic Era. The days were hot, the nights, cold.

"Recent discoveries like Kongonaphon have given us a much better understanding of the early evolution of ornithodirans," Kammerer said. The ornithodiran group includes animals in the evolutionary¹⁰ lineage that led to dinosaurs and pterosaurs. He added that the research provides strong evidence that the creature "decreased sharply early in the history of the dinosaur¹-pterosaur lineage."

On the lighter¹¹ side, Kammerer told The Associated Press he thinks the tiny creatures "would have been quite cute animals." He said an animal that looks like a dinosaur and can fit in your hand, "would probably make a great pet."

I'm Bryan Lynn.

Words in This Story

fossil – n. part of an animal or plant from thousands of years ago, preserved in rock

evolve – v. to develop over time

miniaturized – adj. very small

gigantic – adj. extremely large

fuzzy – adj. covered with light, loose hairs or fibers¹²

feather – n. any one of the light growths that make up the outer covering of the body of a bird

1 dinosaur   

n.恐龙

参考例句：

• Are you trying to tell me that David was attacked by a dinosaur?你是想要告诉我大卫被一支恐龙所攻击？
• He stared at the faithful miniature of the dinosaur.他凝视著精确的恐龙缩小模型。

2 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》

3 reptile   

n.爬行动物；两栖动物

参考例句：

• The frog is not a true reptile.青蛙并非真正的爬行动物。
• So you should not be surprised to see someone keep a reptile as a pet.所以，你不必惊奇有人养了一只爬行动物作为宠物。

4 bug   

n.虫子；故障；窃听器；vt.纠缠；装窃听器

参考例句：

• There is a bug in the system.系统出了故障。
• The bird caught a bug on the fly.那鸟在飞行中捉住了一只昆虫。

5 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。

6 proceedings   

n.进程，过程，议程；诉讼(程序)；公报

参考例句：

• He was released on bail pending committal proceedings. 他交保获释正在候审。
• to initiate legal proceedings against sb 对某人提起诉讼

7 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。

8 Christian   

adj.基督教徒的；n.基督教徒

参考例句：

• They always addressed each other by their Christian name.他们总是以教名互相称呼。
• His mother is a sincere Christian.他母亲是个虔诚的基督教徒。

9 uncommon   

adj.罕见的，非凡的，不平常的

参考例句：

• Such attitudes were not at all uncommon thirty years ago.这些看法在30年前很常见。
• Phil has uncommon intelligence.菲尔智力超群。

10 evolutionary   

adj.进化的；演化的，演变的；[生]进化论的

参考例句：

• Life has its own evolutionary process.生命有其自身的进化过程。
• These are fascinating questions to be resolved by the evolutionary studies of plants.这些十分吸引人的问题将在研究植物进化过程中得以解决。

11 lighter   

n.打火机，点火器；驳船；v.用驳船运送；light的比较级

参考例句：

• The portrait was touched up so as to make it lighter.这张画经过润色，色调明朗了一些。
• The lighter works off the car battery.引燃器利用汽车蓄电池打火。

12 fibers   

光纤( fiber的名词复数 )； （织物的）质地； 纤维，纤维物质

参考例句：

• Thesolution of collagen-PVA was wet spined with the sodium sulfate as coagulant and collagen-PVA composite fibers were prepared. 在此基础上，以硫酸钠为凝固剂，对胶原-PVA共混溶液进行湿法纺丝，制备了胶原-PVA复合纤维。
• Sympathetic fibers are distributed to all regions of the heart. 交感神经纤维分布于心脏的所有部分。