about 19 million years ago in the world Ocean there was a massive extinction of sharks, reported on the portal phys.org.
This fact was established by the University of Yale University, when the teeth of fish and scales of sharks were studied to 85 million years old, taken from deep-sea deposits. When studying, in order to understand the normal variability of this population, a sudden reduction in the number of sharks was discovered about 19 million years ago.
According to their data, about 70 percent of all sharks on the planet died out. It is noted that at that time the ocean was 10 times more sharks than now. However, the cause of extinction is still unknown. Scientists have no information about any climatic disasters or the destruction of the ecosystem in those times. It is only known that most sharks died in the open ocean, and not in coastal waters.
Taking into account the current reduction in the shark populations, the data on such a long extinction causes anxiety scientists. They have to understand what consequences may follow a sharp reduction in the number of these marine predators in our time.
In November, Spanish paleontologists explained the possible reason for the extinction of the largest prehistoric sharks in the history of the Earth about three million years ago. The climate cooling led to a decrease in the sea level, resulting in less coastal zones suitable for their mature young.