Moscow. June 6. INTERFAX.RU – Scientists at Yale University have established that about 19 million years ago there was a massive extinction of sharks, according to the scientific information portal Phys.org.
“This happened in a period of history when 10 times more sharks plowed the world's oceans than today. At the moment, researchers do not know the reasons for the extinction of sharks. More than 70% of sharks in the world are extinct,” the report says.
Moreover, most of them died in the open ocean, and not in coastal waters, paleontologists emphasize. Experts studied fossil teeth and scales of fish up to 85 million years old, and at a level corresponding to a period of 19 million years ago, they found traces of an extinction, which turned out to be twice as large as that which occurred 66 million years ago, when the dinosaurs disappeared.
“Added to this mystery is the fact that neither the climate disaster nor the destruction of the ecosystem that occurred during the sharp decline in shark populations was known,” the message says.
The researchers noted that past discoveries of extinction events have led to waves of new research to find out the causes of extinction and its links to previously unknown disturbances in global ecosystems. For example, further research could confirm whether the extinction of sharks caused remaining populations to avoid the open ocean, and also help explain why there was no recovery of populations after the extinction 19 million years ago.
