90% of sharks mysteriously wiped out nearly 20 million years ago: researchers
An extinction event about 19 million years ago decimated wild-nature populations by up to 90%, researchers say. In a paper published Thursday in the journal Science, Yale University planet-earth and digging-history” target=”_blank”>paleontologist< By studying shark teeth and other marine microfossils buried in deep-sea Pacific sediment, the pair reportedly found that current shark diversity was just…