The biological evolution of the Phanerozoic, and in what age did humans appear in the Phanerozoic?

Based on the fossil material of Australopithecus and hominin that has been discovered, the earliest humans may have appeared 3 million or 4 million years ago. At that time, the Earth was at the end of the Tertiary Period of the Cenozoic Era (65 million years ago, 2.6 million years ago). Therefore, humans appeared at the end of the Tertiary period of the Phanerozoic era on Earth.

Geological chronology.

Paleozoic: The first generation of the Phanerozoic. It began about 100 million years ago and ended 100 million years ago.

It is divided into Cambrian, Ordovician, Silurian, Devonian, Carboniferous and Permian. During this period, the biological world began to flourish. The fauna is dominated by marine invertebrates, and the vertebrates include fish and amphibians.

Plants include ferns and stone pines, and pines and cypresses also appeared during this period. It is named for the fauna of this time, which shows an ancient appearance.

Mesozoic: The second generation of the Phanerozoic. It is divided into Triassic, Jurassic, and Cretaceous.

It began about 100 million years ago and ended 65 million years ago. The main animals of this period were reptiles, dinosaurs flourished, and mammals and birds began to appear. Invertebrates are mainly ammonites and arrowstones.

The plants are mainly ginkgo, cycads and pines.

Cenozoic: The third generation of the Phanerozoic. It is divided into the Paleogene (Old Tertiary), the Neogene (Neo-Tertiary) and the Quaternary.

From about 65 million years ago to the present day. During this period, there was a strong orogeny in the earth's crust, reptiles in the Mesozoic era were extinct, mammals flourished, and organisms reached a high stage of development, which was close to modern times. Later on, humans appeared.

Phanerozoic refers to the "age of visible life", which began in the Cambrian period hundreds of millions of years ago and continues until now.

The biological evolution events that have occurred since the Phanerozoic are mainly multicellular animals and plants, and the protagonists on the biological evolution stage of the Phanerozoic are no longer prokaryotes and single-celled eukaryotes, but multicellular macroscopic animals and plants. Therefore, people call the geological epoch after the emergence of multicellular animals and plants Phanerozoic.

Specifically, the main events of biological evolution since the Phanerozoic are as follows:

1. The first fish appeared in the world, such as Kunming fish and Haikou fish. They are the product of the Cambrian explosion. 2. The world's first amphibians appeared, such as the fish stone newt, the Chinese newt. They are the product of a Devonian explosion.

3. The world's first mammals appeared, such as the trilodont, Morganmon. They are the product of the Triassic Great Explosion.

4. The world's first primate appeared, such as the delicate tooth beast, the Chinese Aperium. They are the product of the Great Paleo-Near Eruption.

In short, the four major explosion events in the biological world since the Phanerozoic have made the overall evolutionary level of the biological world upward and towards the direction of human beings has climbed to the "four levels".

Phanerozoic is divided into three generations: Paleozoic, Mesozoic and Cenozoic, the term geological age you say is a little ambiguous, the general geological age is translated as geological time, the geological age should be translated as geological chron, the geological age unit has several levels, such as the universe, the era, the era, the epoch, the period, the time, etc., some data will say that the geological era is equivalent to the "generation", but this is not correct, the English translation of "generation" is era, not chron, The epoch is the highest unit of geological time.

Marine arthropods flourished in the early Paleozoic, and there was a Cambrian explosion of life in the early period, with the emergence of arthropods represented by trilobites and large marine arthropods represented by odd shrimps, and the appearance of early fishes, trilobites are representative organisms of the Cambrian and Ordovician, and a few species have continued until the Permian, and trilobite fossils are the standard fossils of the Cambrian and Ordovician. Cambrian sponges and brachiopods flourished, echinoderms began to flourish, Ordovician echinoderms began to flourish, corals appeared (represented by four-shot corals) and flourished rapidly, cephalopods flourished, penstones appeared and flourished rapidly, foraminifera appeared, but at the end of the Ordovician there was the first mass extinction event, the number of trilobites decreased sharply, the Silurian penstones began to flourish, the cephalic beetle fishes flourished, Devonian plants began to land, forming naked ferns, the late Devonian vertebrates landed and amphibians appeared, The emergence of labyrinthic rodents, the flourishing of terrestrial arthropods (insects, etc.), the second mass extinction event (the Fraslang-Famen event, i.e., the F-F event) at the end of the Devonian, the extinction of bamboo stone and foraminifera, and the serious decline in the number of jawless fish and brachiopods. The Carboniferous produced a large number of terrestrial ferns, large true ferns such as seed ferns and koda flourished, a large number of forests were formed in humid areas, and primitive reptiles appeared.

Permian terrestrial gymnosperms flourished, especially in scales, seed ferns, koda, etc., gymnosperms began to appear, brachiopods and mollusks flourished in the ocean, ammonites were differentiated, mesomorphs were differentiated, vertebrates were dominated by reptiles (such as panlodosaurus, cup loonda) and amphibians, and cartilaginous fishes and bony fishes were more prosperous. At the end of the Permian, there was a third mass extinction, with a sharp decline in nautilus, trilobites, gymnosperms, extinction, extinction of corals and transverse corals, and the extinction of more than 95% of biological species, especially the devastating blow to terrestrial organisms, and a sharp reduction in the number of biological species on earth (called a P-T event or the third mass extinction event).