dinosaur, the English word for dinosaur, comes from the Greek deinos (meaning terror) Saurosc (meaning lizard or reptile). Dinosaurs (excluding birds) are a group of main dragon reptiles that live on land. Their limbs stand upright under their bodies, rather than spread out to their sides. They appeared in the late Triassic Kanian stage, and various dinosaurs quickly evolved into different specialized features, exhibited different body sizes, occupied different niches, and continued to exist in the late Cretaceous Maastricht stage. [1]
There are many types of reptiles living in the same period as dinosaurs, such as ichthyosauria, Canglong, plesiosaurea, pterodactyla and Panlong. Many mass media often classify them as dinosaurs, but they are not dinosaurs in scientific classification. Ichthyosaurs, Canglong and plesiosaurs are all marine reptiles, which do not live on land and do not belong to the main dragons. Pterosaur belongs to the main dragon, which evolved separately from dinosaurs in Triassic, but it was not a terrestrial animal: Panlong lived in Permian, and its genetic relationship was close to that of mammals.
dinosaurs were the dominant terrestrial vertebrates in Mesozoic, especially in Jurassic and Cretaceous. During the Jurassic and Cretaceous, when dinosaurs dominated, almost all land animals over 1 meter in length were dinosaurs, so other animals of the same age were limited by their size development and niche. Mammals, for example, are mostly close to modern rodents, not more than the size of cats. They are carnivorous and live on small animals. Repenomamus giganticus, a giant reptile of Triconodonta, which lived in Cretaceous, is a few exceptions. The giant reptile weighs 12 to 14 kilograms and is known to feed on small dinosaurs such as young parrot-billed dinosaurs.
the dinosaur family is extremely large and diverse. Up to 26, academic research has identified more than 5 genera; According to estimates, the total number of genera that have appeared in the fossil record is about 185, of which 75% have been found. An early study speculated that there were nearly 3,4 genera of dinosaurs, but most of them could not be preserved in the fossil record. As of September 17th, 28, there were 1,47 species of dinosaurs. Dinosaurs were herbivores, carnivores and omnivores. Some dinosaurs walked on two feet, or on four feet, or like sand dragons and Iguanodons, they could switch between two feet and four feet freely. Many dinosaurs had scales, or horns or crowns on their heads. Although dinosaurs are famous for their huge size, many dinosaurs are only the size of humans or even smaller. At present, dinosaur fossils have been found on all continents, including Antarctica. Regardless of their size, dinosaurs had excellent adaptability to land life, but they could not occupy the niche of marine and flying animals.
the origin of the name
in fact, human beings have a long history of discovering dinosaur fossils. Long before the discovery of Iguanodon, Europeans knew that there were many grotesque huge bone fossils buried underground. It was not until paleontologist Mantel discovered Iguanodon and compared it with iguana that the scientific community initially determined that it was a group of extinct reptiles similar to lizards.
in p>1842, the British paleontologist Charles Owen coined the term "dinosaur". English dinosaur comes from Greek deinos (scary) Saurosc (lizard or reptile). For Owen at that time, this "scary lizard" or "scary reptile" refers to a large extinct reptile (but it is not). In fact, not many dinosaurs were found at that time. Since the discovery of dinosaur fossils in Antarctica in 1989, dinosaur remains have been found in seven continents around the world. At present, there are at least 65 to 8 genera of dinosaurs described in the world (species and genera in paleontology, not completely different from the classification of modern animals). Later, scholars in China, Japan and other countries translated it into dinosaurs, because these countries have always had legends about dragons, and they think that dragons are the length of scale worms, and snakes are known as other names for dragons.