During the Mesozoic era, 230 million years ago, there lived a type of reptiles-dinosaurs. Dinosaurs have strong limbs, long tails, and huge bodies. This structure has become a true portrayal of most dinosaurs. They are also diverse and dominant terrestrial vertebrates. Because of their huge stature, most dinosaurs mainly lived in forests or open areas on lakeshore plains (or coastal plains).

In 1841, when British scientist Richard Irwin studied several fossils resembling lizard bones, he believed that they were left by some prehistoric animal and named them“dinosaurs”, meaning "horrible lizards." The earliest dinosaurs appeared in the Triassic period 230 million years ago and extinct in the late Cretaceous period about 65 million years ago.

At the end of the Cretaceous period 65 million years ago, the sudden collective disappearance of such creatures as dinosaurs is a mystery in the evolutionary history of earth's creatures. But the most famous is roughly the following. 

1. Natural causes

Mainly include climate change, continental drift, geomagnetic change, angiosperm poisoning, acid rain, meteorite impact, volcanic eruption, ocean ebb, and atmospheric changes. Among them, climate change and meteors hitting the earth are the causes of extinction that are generally highly supported. According to media reports, scientists’ latest findings indicate that 65 million years ago, a large-scale meteor impact was the chief culprit in the death of the dinosaurs. The collision will not only bring sudden disasters to the dinosaurs, but also cause a series of post-collision effects, such as changing the climate, environment, and ecosystems.

2. Own reasons

Dinosaurs are creatures with almost no natural enemies. After analysis, scientists have concluded that the high probability of their extinction is due to their own reasons such as aging and cannibalism, which frustrated reproduction and eventually led to the extinction of dinosaur species.

T- Rex

It is survived in the Maastricht period (MAA) at the end of the Cretaceous period, about 68.5 million to 65 million years ago, is one of the last non-avian dinosaurs before the extinction event. Fossils are distributed in North America, the United States, and Canada, and are one of the last dinosaurs to be extinct. T- Rex is the largest species in the Tyrannosaurus family. The body length is about 11.5-14.7 meters. The average hip height is about 4 meters. The highest hip height can reach about 5.2 meters, and the highest head height is nearly 6 meters. The average weight is about 9 tons (the ecological average is about 7.6 tons), the heaviest is 14.85 tons, and the maximum head length is about 1.55 meters. The bite force is generally 90,000 Newtons to 120,000 Newtons, and the mouth end can reach about 200,000 Newtons. It is also the strongest carnivorous dinosaur. T- Rex was located at the top of the food chain in the late Cretaceous, and various dinosaurs in North America could basically be its hunting targets. 

Stego

It is a huge herbivorous dinosaur that lived in the Late Jurassic. It has a row of huge bony plates on its back and a dangerous tail with four spikes for defense against the attack of predators. It is about 7-9 meters long, 2.35 meters to 3.5 meters high, and 2 to 4 tons in weight. They live on the plains and live with other herbivores (such as Diplodocus) in a nomadic manner.

Tricera

It is a medium-sized quadruped dinosaur with a total length of 7-9 meters, a height of 2.4-2.8 meters, and a weight of 5.5-10 tons. They have a very large head shield and three horns, reminiscent of modern rhinos. The most distinctive feature of Tricera is their horns and neck shield. Their head shield can grow to more than 1.5 meters. Tricera has a horn above the snout and nostrils; and a pair of horns above the eyes, over 80 cm. Behind the skull is a relatively short bony head shield, with short limbs, five short toes on the forefoot, and four short toes on the back of the foot.

Diplo

It means "seismic lizard". It was first discovered in New Mexico, the USA in 1979, in the late Jurassic period. The body parts of diplo have been found in the tail; back; hips and hind limbs. The earthquake dragon has a long neck, a small head, and a slender tail. Nostrils grow on the top of the head. Its head and mouth are very small, with flat round teeth at the front of the mouth and no teeth at the back. The front legs of the earthquake dragon are shorter than the hind legs. Each foot has 5 toes, one of which has a claw. The earthquake dragon walked on four feet and walked very slowly. They live in groups. Earthquake dragon is a plant-eating animal. When eating, the earthquake dragon swallows the whole leaves without chewing. It is one of the larger dinosaurs in the dinosaur family.

Ankylo

It is a type of dinosaur that feeds on plants and wears "armor". They are generally five or six meters long, their hind limbs are longer than their forelegs, and their bodies are bulky. They can only crawl slowly on the ground with their limbs. They look a bit like tank cars, so some people call them tank dragons. The upper part of Ankylo's body was covered with thick scales, there were two rows of spines on its back and a pair of horns on its head. Ankylo has a tail like a golf club. Its four legs and neck are short, and its head is broad. Ankylo lived in the late Cretaceous period, and there were many carnivorous dinosaurs. Its bones, nail-shaped bone plates, and hammer-shaped tail (also known as tail hammer) can provide good protection. Its bones were excavated in Montana and belonged to the last extinct group of dinosaurs. The most obvious feature of Ankylo is its armor, which contains solid nodules and decks, embedded in the skin. Ankylo was named by American paleontologist Barnum Brown in 1908. The genus name is derived from the ancient Greek word "αγκυλο" (meaning "buckled").

Para

It is an ornithopod dinosaur that lived in the late Cretaceous period. It is a typical representative of hadrosaurs. It lived in North America, about 76.5 to 73 million years ago. The most distinctive feature of Para is the crown extending from its head. This crown is rod-shaped and longer than other crowned dinosaurs. Para is a herbivorous dinosaur that can walk on two or four legs.

Dinosaurs are a kind of huge creatures that existed in prehistoric times. The above are only representative of several different kinds of dinosaurs. For humans now, we have not experienced the life of dinosaurs, and we can only learn more information about this species through the continuous discoveries of scientists. Humans are advanced animals with strong learning ability, but for children's learning, having a realistic and detachable magnetic toy will undoubtedly make the understanding of this species and the learning of body structure more effective.