British researchers found that was the cause of the Devonian extinction happened 359 million years ago. Their article is published on the website Science Advances.
It is argued that the most likely cause of one of the largest extinctions of life in the history of the planet had effects of UV light. Radiation was deadly for most of the living creatures of the Devonian period in connection with the depletion of the ozone layer caused by global warming — part of the natural cycle of the Earth.
The researchers found samples of fossilized plants, presumably Devonian period, East Greenland and in the Andes in Bolivia. Upon dissolution of the fossils in hydrofluoric acid, scientists were able to isolate spores of ancient plants. These disputes differed unusual shape, especially the shape of their spikes.
According to researchers, improper form debate has turned out subsequently damage their DNA under ultraviolet light. Also, many of the sample dispute found pigmentation, which evolved as a protective mechanism against high levels of ultraviolet radiation.
Radiation was detrimental to flora and fauna on land and in shallow water. Some plants managed to survive, but the forest ecosystem has been undermined. Extinction touched a four-legged and dominating fish group placodermi, the latter was replaced by sharks and bony fish, which have managed to survive and maintain a dominant position among the fish in the current ecosystems.
Scientists emphasize, that the sharp warming of the planet, the ozone layer naturally breaks down, which means "inescapable conclusion" about the necessity of realizing that such cases may happen again.
