What are the types of dinosaurs?

There are many types of dinosaurs. Scientists divide them into two major categories based on the shape of their bone fossils, one is called ornithosaurs, and the other is called saurosaurs. Based on their tooth fossils, it can also be inferred whether they were carnivorous or herbivorous. This is only a rough classification. Based on the recovery of dinosaur bone fossils, we have found that not only are there many types of dinosaurs, but their shapes are even more bizarre. Some of these dinosaurs fly in the sky, some swim in the water, and some crawl on land. Let’s get to know each other briefly!

Classification

It is classified as a general order in biology. The biggest difference between dinosaurs and other reptiles is their standing posture and the way they move. Dinosaurs have a completely upright posture, with their limbs built directly underneath their bodies. This structure is more advantageous for walking and running than other types of reptiles, such as crocodiles, whose limbs extend outward. According to the different structural characteristics of dinosaur belts, they can be divided into two categories: Saurischia and Ornithischia. The main difference between the two lies in the structure of the girdle: the saurischian girdle is three-shot when viewed from the side, with the pubic bone extending forward under the intestinal bone and the ischium extending backward. This structure is similar to that of a lizard; it is very ugly. In ornithischian girdle, the intestinal bone is greatly expanded front and back. There is a large prepubic process on the front side of the pubic bone, which extends below the intestinal bone. The posterior side is greatly extended parallel to the ischium and extends to the front and lower side of the intestinal bone. Therefore, the pelvis is radial when viewed from the side (among other differences). The order Sauropoda is divided into Sauropoda and Theropoda. Sauropods are further divided into prosauropods and sauropods. Prosauropods mainly lived from the Late Triassic to the Early Jurassic. They were a type of omnivorous-vegetarian medium-sized dinosaurs, such as the first giant dinosaur to live on the earth---- Plateosaurus, an angelosaurus that lived in the early Jurassic period. Sauropods lived mainly during the Jurassic and Cretaceous periods. Most of them were giant vegetarian dinosaurs. It has a small head, long neck, long tail, and small spoon-shaped teeth. The famous representative of the sauropods is Mamenchisaurus, which was produced in the Late Jurassic of Sichuan and Gansu, my country. It consists of 19 cervical vertebrae and its neck length is approximately equal to half the body length. It is the largest animal known in the world ----- Seismosaurus or Fragile Amphora, etc. Theropods lived from the Late Triassic to the Cretaceous. They are all carnivorous dragons, walking on two legs, with sharp claws on their toes and well-developed heads. They are the most intelligent ones. The mouth has sharp teeth like daggers or knives. Tyrannosaurus rex is a famous representative, and others such as Allosaurus and Giganotosaurus are also quite famous. Ornithischia is divided into 5 major categories: Ornithopoda, Stegosauria, Ankylosauria, Ceratopsia and Pachycephalosauria. Ornithopods are the group with the most fossils among ornithischians and even among the entire dinosaur class. They walked on two or four legs. The mandible had separate predentary bones. The teeth only grew on the cheeks. The crowns of the upper teeth were curved inward and the crowns of the lower teeth were curved outward. They lived from the Late Triassic to the Cretaceous, and were all vegetarian dinosaurs. Such as: Hadrosaurus, Iguanodon, etc. Stegosaurs walked on four legs, had upright bony plates on their backs, and had two or more pairs of bone spurs on their tails. Stegosaurs mainly lived from the Jurassic to the Early Cretaceous, and were the first large group of dinosaurs to go extinct. . Representatives include Stegosaurus, which is thought to have lived on the plains, and Kensaurus, which was found in Tanzania. Ankylosaurus dinosaurs were short and stocky, covered with bony decks, and fed on plants. They mainly appeared in the early Cretaceous period. For example, Hyrulesaurus lived in continental Europe, Spiny Ankylosaurus lived in the United Kingdom, as well as Baocephalosaurus in the United States and Edmontosaurus in Mongolia. Ceratopsians are vegetarian dinosaurs that walked on four legs. The back of the skull expands into a cervical shield. Most of them lived in the late Cretaceous. The Psittacosaurus found in northern my country is the ancestor of the ceratopsians. Among them are Triceratops, which is as famous as Tyrannosaurus rex, Protoceratops, a docile herbivore, and so on. The main characteristics of pachycephalosaurs are that their skulls are swollen and thick, the foramen is closed, the pubic bone in the osseous plate is crowded out by the ischium, and it does not participate in the formation of the belt. It mainly lived in the Cretaceous period. Whether it is saurischians or ornithischians, their girdle leaves a small hole between the intestinal bone, ischium, and pubic bone. This hole is not found in other reptiles. It is this hole that shows that the two orders of animals known as dinosaurs are the closest relatives to each other compared to all other orders of reptiles.