CRI听力: Fossils in South Africa

The Langebaan Lagoon in South Africa is famous for its dazzling blue waters surrounded by a mass of arid land and barren sand dunes. But five million years ago the area was covered in swamps and teaming with wildlife. Paleontologists say more than 200 species lived in the area, but became extinct because of climate change.




Today the area is relatively cool and dry. Five million years ago it was warm and wet and inhabited by now extinct animals.

Paleontologists study fossils that are often compared to contemporary bones in order to identify them. The soil sediment around fossils is often used as a means of determining their age.

All of this examination allows scientists to understand how the earth has changed over time. Frances Forrest is a doctoral student in paleoanthropology.

"What we're finding is a lot of bovines which would be things like antelopes, and a lot of horse remains. So as you can see the environment today wouldn't be able to support those types of animals, because there's not the type of food that they would be eating. And so since then the environment has changed dramatically. Back then we would have been able to have horses in this area, but today they just wouldn't be able to survive here."

A grassier environment a million years ago would have supported creatures like giant elands and three-toed horses.

Fossils of these mammals and some of the more than 200 extinct animals believed to have existed in the area in the past have been unearthed. The saber-toothed cat and the African bear, which are both now extinct, were also once found in this region.

Pippa Haarhof, Director of West Coast Fossil Park in South Africa, explains why paleontology is important.

"It helps us understand the origins of life on earth, evolutionary trends, extinction events. All those topics help us understand, basically, how life on earth works, gives us a better understanding of where we are now, and what possibly could happen in the future."

Visitors taking a tour through the West Coast Fossil Park learn that animals died in this area five million years ago were quickly covered by sediment in the swamps that existed then. Because the animals were rapidly buried, the fossils are very well-preserved.

What also makes the Fossil Park stand out is its mixture of both marine and terrestrial fossils. These range from whales and giraffes to birds and frogs. For visitor Yolanda Louw, the potential devastation of climate change is brought home by a visit here.

"It definitely brings to life the fact that the climate can change dramatically. I mean, you know, the subtropical to quite a barren climate. And one worries about what's happening to the earth, and what other changes will happen, not in my lifetime but in many years to come."

For China Drive, I am Li Dong.