readx;? The Triassic period (about 251 million years ago - 200 million years ago) was the first epoch of the Mesozoic Era. Pen × fun × Pavilion www. ｂｉｑｕｇｅ。 info Before the end of the Permian, land masses collided and bordered each other to form the massive continent Pangea.

Pangea was bounded by Eurasia in the northernmost, Australia, Antarctica, and India in the southernmost, and the Americas in the west, while present-day Indonesia was located in the easternmost part of the entire continent, connected to present-day Eurasia. Most of the southeastern part of ancient China was covered by the ocean, ancient Turkey and ancient Persia were islands in the ancient Mediterranean, these land masses were not yet connected to ancient Eurasia, the ancient Arabian Peninsula was a corner of ancient Africa, and ancient North America was close to and sometimes connected to ancient Eurasia. The formation of a narrow ocean trench in Madagascar in eastern Africa indicates that the interior of the Gondwana continent has begun to disintegrate. Rain and fog from the sea can no longer penetrate deep into the interior. Some areas are becoming drier and hotter, resulting in more extensive deserts.

In the early Triassic period, the fern forest disappeared into a desert. Swamps and lakes are drying up, depriving herbivorous insects and amphibians of their food. The dry climate at the end of the Permian continued into the Early and Middle Triassic, and the climate transitioned to damp heat, which led to the development of xerophytic plants to damp-heat plants. It was not until the late Middle Triassic that plants began to flourish gradually. In the Late Triassic, gymnosperms really became the main rulers of continental plants. Bennecycads occur in Triassic gymnosperms. Cycads, bennecycads, niersans, ginkgo biloba and pine cypress became the main gymnosperm types.

Among the invertebrates, ammonites, bivalves, and foraminifera are the mainstays, while the scorpion and the four-shot coral are completely extinct.

Osteous fishes first appeared in the Triassic.

Reptiles rose in the Triassic. The lower class of Protosaurus is divided into Alodontes, Pterodactyls, Dinosaurs, and Alligiformes. The order Pterodactyls are divided into primitive beak-billed dinosaurs and advanced pterosaurs. The crocodile order is divided into three families: alligators, crocodiles, and alligators. The general order of dinosaurs is divided into ornithischian orders, theropods, and sauropods. Ornithischian is divided into ornithopods, stegosaurus, ankylosaurs, ceratosaurs, and swollencephalosaurs. Finnid dragons include Sauridae, Phantom Dragons, Plesiosaurs, and Sauridae.

A small number of diodonts survived the Permian-Triassic extinction event, one of which was called the Hydrosauridae, which later developed into the Ken's Zodiacidae. These later animals, which were large, bulky, beak-mouthed animals, remained the dominant herbivorous animals on land. It did not decline until the late Triassic period, and finally perished, and the ecological niche was replaced by sauropod dinosaurs.

Heterodontidae continued to flourish in the Triassic.

A small number of eutheric species survived until the early Triassic and continued to diversify and extinct in the middle Triassic.

The earliest mammals evolved in the late Triassic from the eucandont in reptiles.

In the Karnik Tier of the Late Triassic, about 220 million years ago, true mammals appeared.

Canines evolved into mammals, probably accustomed to moving at night. In order to survive at night, primitive mammals had to increase their metabolic rate at night to maintain body temperature. This means that people consume food more quickly (and feed more on insects). To promote rapid digestion, primitive mammals evolved chewing with specialized teeth to assist with chewing. The ankle arms also evolved under the body rather than the sides. This allows primitive mammals to change direction more quickly to catch small prey. In contrast to fast-running predators, primitive mammals adopted a strategy of mobility.

Sometimes the natural selection of living beings is somehow similar to the principles of quantum theory. Nature at that time had a variety of animals ranging from large to small in size, providing almost every possible sample of choice, similar to the infinite possibilities of quantum theory. It's amazing why nature chose a mouse-sized mammal to survive and develop as the ancestor of modern mammals. The specific reasons are explained in more detail later.

Early Triassic early dragon subclass appeared. Alodontida is a type of early dinosaur that appeared in the early Triassic, and by the late Triassic, the general order of dinosaurs ornithischians, theropods, and sauropods appeared. The Archosaurus subclass became the dominant terrestrial animal. The dinosaurs in the Protosaurus subclass became the dominant terrestrial fauna from the late Triassic to the end of the White Age. Therefore, the Mesozoic Era is sometimes referred to as the "age of dinosaurs" and "the age of reptiles".

The other phyla of the subclass Ichthyosauridae and Cangdae all appeared in the Triassic. Faced with competition from the primosaurus, the Triassic terrestrial subclass began to return to the ocean, and the subclass became the dominant animal in the ocean.

The ichthyosaurs of the subclass Tunkorea were completely specialized into fish-shapes in the early Triassic and occupied a dominant position in the ocean.

Ichthyosaurs are highly adapted reptiles to marine life and resemble fishes. Ichthyosaurs lived in the sea as early as 230 million years ago and fed on mollusks. The mother ichthyosaur lays eggs in her own body, of course, only one egg at a time, and raises them in her body until the baby ichthyosaur hatches. When their children are born, they live in the ocean for the rest of their lives. They are very comfortable in the sea, and some ichthyosaurs can grow to more than 13 meters.

The plesiosaur that appeared in the Triassic period was shaped like a snake passing through a turtle shell: a small head, a long neck, a torso-like torso, and a short tail. Although the head is small, the mouth is large, and there are many slender tapered teeth in the mouth, and it is a fisherman. Many species have very large bodies, up to 11~15 meters long, and some species up to 18 meters. The limbs were specialized into fleshy flippers suitable for paddling, allowing plesiosaurs to move freely in the water and climb ashore. The way in which ichthyosaurs breed offspring is the same. Plesiosaurus may be the prototype of Emperor Zhenwu in Chinese myths and legends. Perhaps the ancestors found the fossilized skeleton of the plesiosaur and offered it to the people.

The Lower Class Lepidsaurus includes the vast majority of members of extant reptiles. These include wedge-toothed, lizards, chameleons, geckos, and snakes, among others.

The mass extinction of life at the turn of the Triassic to the Jurassic (208 million years ago). The catastrophe caused the extinction of 60 families of marine life, and the extinction rate of families was about 1/4. Odontoliths are all extinct, and ammonites, sponges, cephalopods, brachiopods, and insects are all extinct. The alveolar tooth in the lower class of the first dragon was extinct, and the phantom dragon class of the subclass of the subclass was also extinct.

Although the loss of this mass extinction was relatively small, it freed up many "ecological niches" and provided favorable conditions for the emergence of many new species. It was at this time that the dinosaurs began their quest to dominate the earth.

At the end of the Triassic, there was a typical ice age of global dry and cold (a great drought on land) and a significant drop in sea level, followed by a significant increase in temperature, which caused a large rise in sea level (flooding caused by heavy rainfall on the continent). At the same time, it is accompanied by the phenomenon of severe hypoxia in seawater. This two-act catastrophe is similar to the phenomenon of the Ordovician Ice Age extinction event.

Because of the original ability to resist risks, the continental shelf area is too small due to the existence of Pangea, and there is a lack of living space. Therefore, once the wind blows, it is easy to be destroyed. On the mainland, there is little change because of the environment. So the losses are not big.

After this disaster, the oceans were emptied, and there was more room for the subclass to develop in the ocean. And the development space of the first dragon on land is also greater.

The next chapter deals with the Jurassic period in which reptiles are in full swing.

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