For much of the last 400 million years, Antarctica was a warm place, covered with forests and animals. Due to the movement of continents, Antarctica moved from the equator (赤道) to the South Pole, where it is now. Today, Antarctica is the coldest continent on the planet, almost completely covered by a layer of ice, and entirely lacking of animals aside from a few penguins and small insects in the coastal areas.
But it wasn't always that way. Antarctica was once part of the supercontinent (超大陆) named Gondwana, which lasted up until about 160 million years ago, when it slowly began to break up. Gondwana included many continents, such as South America, Africa, Arabia, India, Australia, and New Zealand. Gondwana was one of the world's two supercontinents, and the other was Laurasia, which included present North America and Asia. It is reported that fossils of some of the earliest life have been found in the surrounding shallow seas. Much of the fossil record of the Antarctica is under the ice, but fossils, including those of dinosaurs, can be found in the Antarctica mountains.
As Antarctica began to break away from the supercontinent Gondwana 160 million years ago, cooling began. It moved towards south, still connected to Australia and South America but separated from Africa. At this point, Antarctica still had a tropical (热带) or subtropical (亚热带) climate, but it was located further south, near the latitude (纬度) of present Australia. Like today's Australia, there were many plants on the continent.
Around 40 million years ago, Antarctica separated from today's Australia and began to cool down even more, its forests dying. Ice and glaciers began to cover the continent, but the final end of Antarctica's life came only about 23 million years ago. It resulted in the continent being covered in a miledeep layer of ice, as the snow never melted. Today, Antarctica's ice sheet contains about 70% of all fresh water on Earth.
Section_ⅠIntroduction_&_Reading_—_Prereading
