As mentioned in the previous article, some organic molecules generated by chemical reactions gradually evolved into life, so how did life continue to reach glory after that? After the birth of life, our world entered the Paleozoic.
Ancient creatures discovered so far by paleontologists date back to 635 million years ago in the Obabin sea scorpion, and these earth's earliest creatures lived much like today's sponges, with roots stuck in the ocean floor and filtering food particles from the water.
Obapibin Sea Scorpion
In 1909, the American paleontologist Charles Walcott discovered the Burgess Shale rock in the Burgess Pass in British Columbia, Canada, and saw the oldest known evidence of many of the animal groups recorded at the time in the rock blocks, and this study found that this study is what we call the Cambrian explosion of life. In the fossil record of the Cambrian Period (about 542 million to 490 million years ago), a variety of animals with complex structures suddenly emerged on Earth.
The Ordovician period, which began 500 million years ago, was a period dominated by invertebrate organisms, during which algae did not change much, and trilobites still ranked first in numbers. At this time other invertebrates outnumbered and species in Cambrian. The most common are corals, brachiopods, gastropods, sea lilies and nautilus. The Earth's land changes little during the Ordovician period due to the constant photosynthesis of aquatic plants. The oxygen content in the air is further increased. Roughly less oxygen than the top of Mount Everest, the vast sea is home to a large number of invertebrates of various classes, and in addition to the Cambrian period, certain taxa have been further developed, such as penstones, corals, brachiopods, sea lilies, mosses and mollusks.
Trilobite fossils
After a long period of evolution, the Earth entered a period dominated by vertebrates, what we call the Silurian Period (440-410 million years ago), when marine invertebrates underwent an important renewal, the flourishing trilobites gradually declined, and the plate-footed horseshoe began to rise, which was the largest species of marine arthropods at that time. Along with the development of terrestrial plants, the earliest insects and arachnid arthropods also appeared in the late Silurian period. The biggest feature of this period is that plants began to land, and in the sea also appeared fish with jaws - spiny fish, spiny fish and evolved gill caps, and there were groups of corals in the sea that gathered to live, and finally formed coral reefs.
Gradually, fish became the hegemon of this period, ushering in the Devonian Period. This period is the period of vertebrate overflight and development, fish are quite prosperous, and various types of fish have appeared, so the Devonian period is called the "age of fish". The early Devonians were mostly jawless, and the middle and late Devonian shield fish were quite prosperous, and they already had primitive jaws, even fins developed, and formed a crooked tail.
About 367 million years ago, huge meteors broke through the night sky and fell into the sea, and lightning flashed in the sky. At this time, the global climate has dried up and the temperature has dropped. Ocean currents vortex in new forms, cooling the oceans further, the salinity of surface water is higher, and the oxygen content in the oceans drops to very low levels. At least 3 or more giant objects from space crashed into the ocean during this period, resulting in the extinction of many marine organisms, including reef-building animals, a variety of fish and brachiopods.
In the late Devonian period, many species of fish were also threatened as the Earth's climate became harsher and the lakes dried up. Over time, some of the branches of the total fin fish adapted well to the environment, relying on even fins, inner nostrils and maws to climb onto land in search of water and food, and over time some of them evolved into primitive amphibians.
Amphibians appeared in the late Devonian period
About 363-251 million years ago, our planet ushered in the last two paleozoic epochs, the Carboniferous and Permian.
During the Carboniferous period, the climate was humid, so new and peculiar forests appeared, which were the earliest forests on land. These forests were not as dense and dark as today's swamp forests, and they consisted of wood thieves, thick layers of ferns, and tall, thin trees. New strange animals settled down in this peculiar landscape. Amphibians of all shapes and sizes thrive in moist environments, as do huge insects.
Immediately after that, came the Permian, the last epoch of the Paleozoic Era (the 6th epoch). The Permian is an important period of evolution in the biological world. The main phyla in marine invertebrates are still fluorine, coral, brachiopods and ammonites, but the composition has undergone important changes. Only a few representatives of the trilobites of arthropods remain, and gastropods and bivalves have undergone new developments. At the end of the Permian, the four-shot coral, transverse coral, the russet, and the trilobite were all extinct; brachiopods were greatly reduced, and only a few categories remained.
Vertebrates reached a new stage of development during the Permian. There have been new developments in cartilaginous fish and teleost fish in fish, many new types have emerged in cartilaginous fish, and cartilaginous hard scale fish have developed rapidly. Amphibians further flourished. There were new developments in the cuposaurs of reptiles in the Permian; the Middle Dragons swam in rivers or lakes, represented by the Middle Dragons of Brazil and South Africa; the Panlongs were found in the Late Carboniferous and Early Permians; and the Theropods were mammalian reptiles of the Middle, Late, and Triassic Periods, which were found all over the world.
Cynodontidae marine life
These are the first epochs after the emergence of life on our planet, which we call the Paleozoic era of the Geological Age, and I will introduce how reptiles ruled the earth after the Paleozoic Era.