Hypotheses about the extinction of the dinosaurs

Paleontologists - both professionals and amateurs - put forward several explanations strange disappearance of dinosaurs from the face of the Earth. The ancient ancestors of birds, which previously did not have to like them, dominated the planet for an incredibly long time, and the causes of their death are shrouded in mystery.

The remains of dinosaurs, scientists have begun to study in XIX-th century, and then there were the first hypothesis about the causes of their disappearance. Today, paleontologists know that most of the dinosaurs disappeared about 66 million years ago, after the increase in volcanic activity, climate change and the effects of the fall to Earth asteroid. At that time, disappeared many forms of life, from dinosaur remains only their descendants - the birds. Here are a few versions of the reasons for the extinction of dinosaurs:

1. Eating eggs





Paleontologist George Wieland at the beginning of XX-th century, argued that dinosaurs ate themselves and thereby doomed itself to extinction. According to him, the ancestors of the terrible tyrannosaurs probably made their first step toward gigantism, started eating sauropod eggs. Even the most caring mother dinosaurs could not prevent the poaching of hungry predators.

By the way, modern lizards and snakes can also feed on other people's egg laying. Studies conducted since the emergence of the hypothesis in 1925, confirmed that the dinosaurs and snakes and some mammals that period really ate the eggs and young are tiny, but not in such quantities that it could cause extinction.

2. Deformation of the shell



Expert invertebrate fossil G. K. Erben and his colleagues also believed that eggs contributed to the extinction of the dinosaurs, but not as described in the first paragraph. The newspaper of 1979, researchers published a version of that analysis of the fragments of fossilized eggshells found in the south of France and in the Spanish Pyrenees, showed two kinds of deviations: the shell of some eggs were multilayered and thick, others - an extremely thin.

Any of these situations has been deadly: in multi-layered eggs to suffocate embryos and eggs with thin shells could easily crack and cause dehydration of embryos or become easy prey for a predator.

Researchers felt that some climatic changes could well contribute to the hormonal changes of female dinosaurs, but this explanation is not suitable for other dinosaurs around the world. It seems that the deformation of eggshell was a local phenomenon.

3. Hyperactive cancer



Baron Franz von Fels-Nopksa Tsilvas, an aristocrat of Hungarian origin, was one of the most eccentric paleontologist, and his theory of the extinction were just as unusual. Nopksa at the beginning of XX-th century, suggested that the death of the dinosaurs contributed to the lack of food, inability to resist, and even a decrease in their sexual activity, but his favorite theory was the death of a hyperactive gland.

He believed that dinosaurs grew to epic proportions due to malfunction of the pituitary gland. Finally, iron was the reason that the animals have become abnormally huge and grotesque. Nopksa tried to link human pathology mystery of dinosaur extinction, but there is no reliable evidence that the pituitary gland could have an impact on the size or disappearance of the dinosaurs.

4. Evolutionary self-destruct



There is a theory that certain types of living beings "go through the Dinosaurs" - in other words, in the course of evolution becomes too sluggish, stupid or small to survive. For some time, paleontologists have thought that this is what happened to the dinosaurs.

In the early 1900s, when Darwin's theory of natural selection is still not fully recognized in the scientific community, many paleontologists believed that organisms have evolved in close relation to each other. According to this theory, the view that dinosaurs had a kind of evolutionary inertia, forcing them to become bigger and stranger still was debunked.

Some researchers have even suggested that the dinosaurs in comparison with the mammals were dumb, because too much of their energy is spent on growth. However, the theory can not explain why, in this case, some of the biggest and strange species like Stegosaurus and Brachiosaurus has long thrived on all the earth.

5. Too many males



During the last decade infertility specialist Sherman Silber has repeatedly argued that the dinosaurs died because they could not find a mate.

Silber suggested that, similar to modern crocodiles and alligators, changes in ambient temperature could determine the sex of the embryo during development of the dinosaurs in eggs. In this case, climate change, caused by volcanic activity and the fall of the asteroid could cause the fact that the vast majority of the eggs hatch into males.

However, we still do not know whether the influence on the development of sexual characteristics of dinosaurs temperature or not. In addition, the theory does not explain why reptiles whose embryos are clearly subject to temperature influences, such as the ancestors of modern crocodiles survived, and dinosaurs became extinct almost completely.

6. Track



In a direct battle caterpillar is unlikely to win triceratops. But research from 1962, about the impact of tracks on the balance of nature, spent entomologist Stanley Flanders says that the larvae of moths and caterpillars can quickly reduce the number of plants in the Cretaceous period.

Flanders argued that in this case herbivorous dinosaurs would have starved, and thus predatory species too soon would have nothing to eat - except each other. The weak point of the theory that a butterfly coexisted with dinosaurs for millions of years, and finds fossils of insects do not show an increase in the number of tracks at a time.

7. Cataract



Most versions of the death of the dinosaurs was based on the personal experience of those who express them. It is not surprising that in 1982, the ophthalmologist LR Croft suggested that the reason for the extinction of dinosaurs was poor eyesight.

Prolonged exposure to heat cataract develops faster and Croft decided that the dinosaurs with horns or crests bizarre color used these "decorations" for protection from the merciless sun of the Mesozoic era. Nevertheless, even this did not save the eye of the dinosaurs, and they eventually lost vision until puberty. But the idea of ​​Croft does not explain the mass extinction of non-winged dinosaurs 66 million years ago.

8. Ultra



Although the hypothesis of the fall of the asteroid is widespread, in 1971, physicist Wallace Tucker and paleontologist Dale Russell offered a different kind of "space" death. Although the researchers did not have enough evidence of their ideas, they suggested that the explosion located relatively close to the solar system supernova at the end of the Cretaceous period could have catastrophic consequences for life on Earth.

The explosion of a supernova upper atmosphere of the planet have been exposed to X-rays and other types of radiation, which led to rapid climate change, and the temperature on the Earth has become a fast fall, but no evidence of such an event was not found.

9. Aliens



The exhibition at the Museum of Prehistory of the College of Eastern Utah shows that the aliens could not destroy the dinosaurs, if only because that has not been preserved fossils themselves are no aliens or traces of their activities. However, the lack of evidence has not stopped some creative people from offering such science fiction scenarios.

Last year, in the television series "Ancient Aliens" the whole episode was dedicated to the idea, based on a misunderstanding and creationist reasoning: the aliens have destroyed all the dinosaurs to make their mysterious cases and free up space for humanity. Apatosaurus not just faced with aliens only in comics and cartoons.

10. fart



Another unscientific hypothesis is that dinosaurs doomed themselves to extinction own farts. Last year, a paleontologist David Wilkinson and his colleagues tried to calculate how much gas could produce an enormous sauropod body with a long neck.

Researchers have suggested that dinosaurs could allocate sufficient methane to affect the global climate. But in the end, the various sauropods lived on Earth for tens of millions of years, showing no signs of gas poisoning themselves. Ignoring the real research, Wilkinson and his colleagues have gathered evidence on thematic sites and has long proven the correctness of the theory.

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