The smallest dinosaur egg was found in Japan. What do you know about dinosaurs?

Dinosaur was a reptile in Mesozoic (230 million years ago). Its vigorous limbs, long tail and huge body are the portrayal of most dinosaurs. They mainly inhabit woodland or open areas in lakeshore plains (or coastal plains).

184 1 year, British scientist Richard? When Owen studied several lizard-like bone fossils, he thought they were left by some prehistoric animals and named them dinosaurs, meaning "terrible lizards".

The sudden disappearance of dinosaurs at the end of Cretaceous 65 million years ago became a mystery in the evolutionary history of life on earth. This mystery has not been solved so far. In the past, all living things on the earth were recorded in fossils. Many dinosaur fossils have been found in Mesozoic strata. A large number of bones or various shapes can be seen in it. However, in the subsequent Cenozoic strata, there were no fossils of non-bird dinosaurs at all, thus inferring that non-bird dinosaurs died out together in Mesozoic, and now only birds are left. Most scientists agree that "birds belong to dinosaurs". There are many kinds of dinosaurs, and their shapes and habits are very different. The largest fragile double-chambered dragon may be more than 50 meters, while the smallest hummingbird may be less than 10 cm. As far as eating habits are concerned, there are docile herbivores and fierce carnivores, as well as omnivorous dinosaurs who are both vegetarian and vegetarian. Ruled the earth for about 80 million years (654.38+44 million years ago-65 million years ago).

Dinosaurs are a diverse group of dominant vertebrates in Mesozoic, most of which belong to terrestrial reptiles. It is said that it is a vertebrate, not a reptile, because dinosaurs were once classified as reptiles, but it does not conform to one of the basic characteristics of reptiles: the crawling way of walking and the cold-blooded animals that have been questioned.

Dinosaurs once ruled the global terrestrial ecosystem for more than 65.438+0.6 billion years. Dinosaurs first appeared in the Triassic period 230 million years ago and died out in the late Cretaceous period about 65 million years ago.