VOA慢速英语2019--四足鲸鱼化石现身南美洲

Fossil¹ Discovery Shows Four-Legged Whale Reached South America

The whales we know today are large, fish-like animals that only live in the sea. But the ancestors of these underwater creatures had legs to carry them on land.

Now, scientists working in South America have reported the discovery of fossils² of a four-legged whale. The scientists believe it lived about 43 million years ago. They say the find is important to helping³ understand the evolution and movements of these early whales.

Paleontologists reported on the discovery in the publication Current Biology. They wrote that a research team discovered the fossils eight years ago in a coastal⁴ desert area of southern Peru. Scientists have been studying them and putting together the skeleton⁵.

The four-legged whale is called Peregocetus pacificus, which in Latin means “the travelling whale that reached the Pacific Ocean.” It was an ancestor of whales that were amphibious, having the ability to live both on land and in water.

Fossil evidence shows that the first such animals appeared about 50 million years ago in areas currently⁶ making up India and Pakistan. The creatures were about four meters long. They were able to carry their own weight and could walk the Earth.

Scientists believe the Peregocetus spent most of its time in the water, but might have climbed onto the rocky coast to rest or give birth. The fossil shows evidence that the animal’s hands and feet had small hooves and their toes were connected to aid in swimming.

Olivier Lambert is a paleontologist at the Royal Belgian Institute of Natural Sciences in Brussels. He unearthed⁷ the fossil and has examined it with other scientists from Peru, Italy and France.

Lambert says the fossil provides valuable information about how these early whales developed and traveled. Finding it in Peru suggests the whales spread from South Asia to North Africa, then crossed the South Atlantic to reach the Americas.

At that time, the distance across the ocean was thought to have been half what it is today. In addition, east-west ocean currents at the time are believed to have helped the whales’ movements. Later, the ancestors of Peregocetus moved further north to reach the east coast of North America.

In the past, fossil remains⁸ of four-legged whales were found in India, Pakistan and parts of Africa. But the African samples were in too many pieces to provide a clear picture of the animals. Lambert called his group’s discovery “the most complete specimen⁹ ever found for a four-legged whale outside of India and Pakistan.”

The scientists say the newly-discovered fossils provide evidence that the whale also had good swimming skills. Lambert said bone parts examined from the tail suggest the whale moved in similar ways to current amphibious animals, such as otters¹⁰ and beavers¹¹.

Lambert says Peru’s Pisco Basin, where the discovery was made, likely holds other fossils that can provide new information about whales and other creatures from the past.

"We have work for at least the next 50 years," he added.

I’m Bryan Lynn.

Words in This Story

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

evolution – n. the way in which living things gradually change and develop over millions of years

paleontologist – n. someone who studies fossils

hooves – n. the hard parts on the bottom of the feet of some animals

specimen – n. an animal, plant, etc. that is used as an example of its type, especially for scientific study

tail – n. the long, narrow part that extends from the back of an animal's body

1 fossil   

n.化石，食古不化的人，老顽固

参考例句：

• At this distance of time it is difficult to date the fossil.时间隔得这么久了，很难确定这化石的年代。
• The man is a fossil.那人是个老顽固。

2 fossils   

n.化石( fossil的名词复数 )；老顽固；食古不化的人；老古董（老人）

参考例句：

• fossils over two million years old 两百多万年的化石
• The geologist found many uncovered fossils in the valley. 在那山谷里，地质学家发现了许多裸露的化石。 来自《简明英汉词典》

3 helping   

n.食物的一份&adj.帮助人的，辅助的

参考例句：

• The poor children regularly pony up for a second helping of my hamburger. 那些可怜的孩子们总是要求我把我的汉堡包再给他们一份。
• By doing this, they may at times be helping to restore competition. 这样一来, 他在某些时候,有助于竞争的加强。

4 coastal   

adj.海岸的，沿海的，沿岸的

参考例句：

• The ocean waves are slowly eating away the coastal rocks.大海的波浪慢慢地侵蚀着岸边的岩石。
• This country will fortify the coastal areas.该国将加强沿海地区的防御。

5 skeleton   

n.骨骼，框架，骨干，梗概，提要

参考例句：

• A long illness made a skeleton out of him.长期的卧病使他骨瘦如柴。
• Her notes gave us just the bare skeleton of her theory.她的笔记只给我们提供了她的理论的梗概。

6 currently   

adv.通常地，普遍地，当前

参考例句：

• Currently it is not possible to reconcile this conflicting evidence.当前还未有可能去解释这一矛盾的例证。
• Our contracts are currently under review.我们的合同正在复查。

7 unearthed   

出土的（考古）

参考例句：

• Many unearthed cultural relics are set forth in the exhibition hall. 展览馆里陈列着许多出土文物。
• Some utensils were in a state of decay when they were unearthed. 有些器皿在出土时已经残破。

8 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。

9 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。

10 otters   

n.（水）獭( otter的名词复数 )；獭皮

参考例句：

• An attempt is being made to entice otters back to the river. 人们正试图把水獭引诱回河里去。 来自《简明英汉词典》
• Otters are believed to have been on Earth for 90 million years. 水獭被认为存活在地球上已经9千多万年。 来自互联网

11 beavers   

海狸( beaver的名词复数 )； 海狸皮毛； 棕灰色； 拼命工作的人

参考例句：

• In 1928 some porpoises were photographed working like beavers to push ashore a waterlogged mattress. 1928年有人把这些海豚象海狸那样把一床浸泡了水的褥垫推上岸时的情景拍摄了下来。
• Thus do the beavers, thus do the bees, thus do men. 海狸是这样做的，蜜蜂是这样做的，人也是这样做的。