The Cenozoic Era, or era of recent life, began about 66 million years ago when dinosaurs and many other life-forms became extinct. Many of the mountain ranges throughout North and South American began to form at this time.
During the Cenozoic Era, the climate became cooler and ice ages occurred. The Cenozoic era is subdivided into two periods. The present-day period is the Quaternary. It began after the last ice age. Many changes in Earth, its climate, and its life-forms, occurred in the Cenozoic Era.
Pangaea broke up during the Mesozoic Era, and continents continued to move toward their present positions.
Times of Mountain Building
The Alps formed as the African Plate collided with the Eurasian Plate. The Himalaya Mountains started to form when the Indian Plate collided with the Eurasian Plate.
As the number of flowering plants increased, their pollen and fruit provided food for the many insects and small, plant-eating mammals. The plant-eating mammals provided food for meat-eating mammals.
Further Evolution of Mammals
Mammals evolved into larger life-forms. Recall how horses have evolved from small, multi-toed animals into the much larger, hoofed animals of today. Not all mammals remained on land. Ancestors of the present-day whales and dolphins evolved to make their lives in the sea.
As Australia and South America separated from Antarctica in the continuing breakup of Pangaea, many life-forms became isolated. They evolved separately from life-forms in other parts of the world. Evidence of this can be seen today with the dominance of marsupials in Australia. Marsupials are mammals that carry their young in a pouch.
Our species, Homo sapiens, probably appeared about 500,000 years ago, but became a dominant animal only about 10,000 years ago. As the climate remained cool and dry, many larger mammals became extinct. Some scientists think the appearance of humans may have led to the extinction of other mammals. As their numbers grew, humans competed for food that other animals relied upon. Also, fossil records indicate that early humans were hunters.
Please answer in one to two complete, quality sentences.
1. What does Cenozoic Era mean? How long ago did it begin?
2. What was the Cenozoic Era’s climate like? What did the continents look like?
3. How did the Alps form?
4. How did the Himalaya Mountains form?
5. What started to evolve as the number of flowering plants increased? Why is this?
6. What happened to mammals during this Era? Did they become more or less abundant after the extinction of the dinosaurs? Why?
7. What mammals did not remain on land?
8. After Pangaea continued to breakup, what mammal became isolated in Australia?
9. How long ago did our species, Homo sapiens, first appear? When did we start to dominate?
10. What do some scientists think happened to other mammals when we became the dominant animal?