The asteroid that killed the dinosaurs, did not touch a life in freshwater?

31.07.2013

 

Scientists now have fresh evidence that the asteroid impact that led to the end of the era of the dinosaurs, occurred near the present city of Chikalaba, which is located in Mexico. This cosmic impact of a ten asteroid killed many creatures on land and in the sea, but scientists have discovered that living organisms, located in a clash in fresh water, managed to avoid this fate.


According to new research, described in detail in the Journal of Geophysical Research-Biogeosciences, as scientists assume, freshwater residents escaped extinction because they were better adapted to the rapid changes in the environment. After carefully considering this global extinction that occurred more than 65 million years ago, experts have concluded that the disaster killed at least 75 percent of all species that lived at the time in the world, among whom were the dinosaurs.

Previous studies have suggested that while the sea life was almost completely destroyed as a result of the mass extinction, freshwater organisms are passed through a relatively low rate of species extinction. Scientists tend to think that the secret of their survival — a remarkable adaptability to external changes.

Water could have saved the lives of many species of living creatures in the rivers and lakes, as well as in the seas and oceans, protecting them from heat stroke. However, as a result of a collision with an asteroid surface of the Earth was on fire, and the dust and ash darkened the sky, which was the reason for the sharp cooling of the planet. The lack of heat and sunlight was the main cause of extinction of species, as the broken food chain because of the death of phytoplankton — microscopic photosynthetic organisms that produce oxygen. But, interestingly, while the residents were marine mass extinction, freshwater residents hardly affected.

It turns out that freshwater organisms, in contrast to the marine flora and fauna, are accustomed to the annual freezing point of water, which severely limits their oxygen supply. Therefore, they are best experienced a sharp decline in the level of oxygen as a result of the death of phytoplankton. In addition, many freshwater organisms can be a long time in hibernation, which allowed them almost without prejudice wait to get back to a comfortable living environment.
 


S. Vasilenko

See also: Secrets of the Pyramids of Giza, ancient artifacts are found.

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