What is the History of the Earth's Crust?
The birth of the universe 15 billion years ago laid the material foundation for the earth. Earth as a planet originated in the primitive solar nebula 4.6 billion years ago.
- Main entry:
- The Tertiary period began 65 million years ago and extends to approximately 1.8 million years ago. The important biological categories of the Tertiary are angiosperms, mammals, birds, true-bone fish, bivalves, gastropods, foraminifera, etc. This is very different from the biological interface of the Mesozoic era, marking the "modern biological era Coming. " Angiosperms flourished in the tertiary period. Except for conifers, which are still important, the other gymnosperms tend to decline. Ferns are also greatly reduced and their distribution is mostly limited to warm areas. Tertiary plants have obvious zoning phenomenon, and there are many micro-aquatic algae fossils in the stratum. The changes in vertebrates are mainly manifested in the decline of reptiles, replaced by mammals, birds and true-bone fish, which have emerged and are highly prosperous. In the early period of the Tertiary period, ancient and primitive mammals were still living; in the middle period, the ancestors of modern mammals appeared successively, gradually replacing the ancient and primitive mammals; in the late Tertiary period, modern mammal groups gradually formed, and more It was a period when cloven-hoofed and proboscis flourished. Especially horses have evolved quickly. [17]
- Main article: Human history
Earth history human origin
- Early human life imagination [18]
- 33 million to 24 million years ago, apes were born. The earliest ancient apes and Egyptian apes found in Egypt already have some of the characteristics of anthropoid apes; later, ancient ape fossils and forest ancient apes are widely distributed, and they have been found in Asia, Europe, and Africa. The original consul ape in East Africa is already an ape, the ancestor of humans and African apes. The above ancient apes are forest-dwelling animals that walk on all fours and belong to the group of apes climbing trees. Existing apes include two groups: African apes (gorillas, chimpanzees, and humans) and Asian apes (gibbons and orangutans). There is a clear boundary between these two groups. Obviously, the differentiation between the two groups occurred at 12 million 15 million years ago.
- From about 10 million years ago to about 3.8 or more than 2 million years ago, there were two types of transitional fossils. One is the Lama ancient ape, and the other is the southern ancient ape.
- The first humans were called "fully formed humans" in anthropology. Chinese ancient anthropologists divide this process into two major stages, ape-human and sapiens, each of which is divided into two periods, morning and evening. 2.5 million years ago, the climate in tropical Africa began to deteriorate, and the glacial period hit the northern hemisphere. As the climate became drier, the savanna began to gradually become shrubby prairie, and most southern ancient apes disappeared. There are two exceptions. One is that some areas of the savanna have been preserved, where the southern ancient apes survived, such as the southern ancient ape and two stout species. A more important situation is that some southern ancient ape groups have used their ingenuity to invent some successful defense mechanisms and survive. For these defense mechanisms, people can only guess, may throw stones, or use wood and other Primitive weapons made of plant materials may be exposed to campfires in the wild. In fact, the descendants of these southern ancient apes survived and prospered, and eventually evolved into the adult genus, changing from biped walking on trees to living on land and walking on both feet.
Era of civilization of earth history
- Main terms: Stone Age, World History, Chinese History, Alexander Empire, Mongolian Expedition, British Bourgeois Revolution, Napoleon Empire, World War I, World War II, American Civil Rights Movement, 9/11, Third World war