About 19 million years ago, there was a massive extinction of sharks in the world's oceans, according to Phys.org.
This fact was established by scientists at Yale University when they studied the teeth of fish and shark scales up to 85 million years old, taken from deep-sea sediments. Studying them in order to understand the normal variability of this population revealed a sudden decline in the number of sharks about 19 million years ago.
According to them, about 70 percent of all sharks on the planet have become extinct. It is noted that during that period, there were 10 times more sharks in the ocean than now. However, the cause of the extinction is still unknown. Scientists have no information about any climatic disasters or destruction of the ecosystem at that time. It is only known that most sharks died in the open ocean, and not in coastal waters.
Given the current decline in shark populations, the data on such a long-term extinction is of concern to scientists. They have to understand what consequences may follow the sharp decline in the number of these marine predators in our time.
In November, Spanish paleontologists explained the possible cause of the extinction of the largest prehistoric sharks in Earth's history about three million years ago. The cooling climate has led to a drop in sea levels, leaving fewer coastal areas suitable for maturing their young.
