A team of scientists from Yale University, in the United States, headed by Elizabeth Sibert, postdoctoral associate at the Department of Earth and Planetary Sciences of that educational center, confirmed the finding after studying the teeth of microfossil fish and scales of sharks in sediments in the deep sea.

Sibert, who is also a member of the Institute for Biospheric Studies from that university, said that by generating a record of 85 million years of abundance of those marine species, it discovered a sudden drop of more than 70 percent in the number of shark specimens.

The higher number of deaths occurred in the open sea compared with coastal waters, a figure that is twice the level of extinction recorded in the Cretaceous-Paleogene period 66 millions ago, which wiped out three-fourths of plant and animal species on Earth, she noted.

Future research will allow confirming whether the deaths of sharks caused remaining populations to change their habitat and why they did not recover after that event 19 million years ago, the publication commented.

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