Dinosaurs became extinct at the end of the Cretaceous Period. Experts are still confused about what caused their extinction. Some believe extinctions caused by meteorites or comets hit Earth and others believe in a more gradual process that must be held responsible, such as the climate between mammals and dinosaurs, or moderate climate change. We can also be sure how long it will take for the extinction to occur. Some believe it happened for half a million years and others say it in just a few days. The extinction event that killed the dinosaurs of all the earth! Plants and animals on land and air. The loss of other living things is so great that it knows about extinction 30 years before the first dinosaurs were discovered.
Lime extinction victims include dinosaurs, ammon (mollusk associated with octopus, and nautilus chamber), pterosaurs, and certain plant groups. Many animals, such as mammals, turtles, crocodiles, salamanders, toads, birds, slugs, bivalves, starfish, and sea urchins. Even some large reptile groups such as champsosaurus, are not important. The dinosaur glory has passed and only the mammalian world like shrew and cold-blooded reptiles is wrong. In fact, many land animals have lived in chalk
Dinosaurs share with modern beings in the last millions of years. Because more than a few dinosaurs went extinct, a reason that only explains why dinosaurs died could be ruled out. For example, there is one theory of disease causing dinosaur extinction. But disease can not cause the extinction of plants and animals around the world. There are two groups of extinction theories: disaster extinction and gradual extinction. The extinction of the disaster will occur by sudden external events, such as a collision of the earth with an asteroid, or a gigantic volcano eruption. Extinction will gradually become the result of changes in land mass and climate change. It could also be because of new animals and better wins in the struggle for existence.
The theory of asteroid space collision originated from the discovery of stone layers dated precisely until the extinction event, and rich in iridium metal. This layer is found all over the world, on land and in the oceans. Iridium is rarely found on Earth but is found in meteorites at the same concentrations as in this layer. This led scientists to postulate the iridium scattered around the world as comets or asteroids hit Earth and then evaporated. The 110-mile (180-kilometer) crater carved on the Mexican Yucatán Peninsula, named Chicxulub, was dated 65 million years ago. Many scientists believe this crater occurred during the extinction of the dinosaurs.
But the core of the earth is also rich in iridium, and its core is the source of magma that some scientists say spit out like floodwaters that accumulate over 1.5 miles (2.4 kilometers) thick over 1 million square miles (2.6 million square kilometers ) from India. The volcanic turmoil has also been dated some 65 million years ago and spreads iridium throughout the world, along with dust and soot that light up sunlight and greenhouse gases.
Until the recent theory of collisions, some ideas about the disappearance of dinosaurs awake around the mammals that defeated them in the struggle for survival. One theory shows mammals killing dinosaurs because they are dinosaur eggs. Other scientists say that dinosaurs caused their own extinction. According to this theory, too many flesh-eating dinosaurs evolved, all plant-eaters, causing all dinosaurs to die. This idea has the same trap as before. They explain the extinction of the dinosaurs but see the extinction of other groups. Events of extinction do not kill all animal and plant life. Many types of animals survive, including fish, frogs, turtles, crocodiles, birds, and mammals. Scientists must take the fossil record and find a reason for all extinction.