Jaws forever changed the way many of us think about sharks. But not in a way that’s fair to the animals. They have a lot more to fear from humans than we do of them. But long before we showed up they faced something far more dangerous than Quint, Hooper, and Brody. A new report says that 19 million years ago, 90% of the planet’s shark population inexplicably vanished. In a “mysterious mass extinction” that greatly reduced shark diversity.
Researchers in Science shared their findings about early Miocene extinction in pelagic sharks. (A study we first came across at Science News.) Yale University paleobiologist and oceanographer Elizabeth Sibert and, at the time, undergrad student at Bar Harbor, Maine’s College of the Atlantic, Leah Rubin, studied shark teeth “buried in deep sea sediment” in two regions of the Pacific Ocean. What they found was “evidence for a previously unknown major extinction event” that occurred roughly 19 million years ago.
The causes of this previously unknown abrupt extinction are a mystery. Sibert and Rubin write “there is no known climatic and/or environmental driver of this extinction.” What they have learned though is that the results were devastating. Not only did it wipe out 90% of the entire shark population, it killed 70% of shark diversity. Modern sharks as we know them began to diversify from the survivors “within two to five million years after the extinction.” However, “they represent only a minor sliver of what sharks once were.”
But this event is just another reminder of how resilient these sea creatures really are. Sharks have been around for at least 420 million years. We know they have “ survived four of the ‘big five’ mass extinctions.” Now we know they also survived their own mysterious personal apocalypse too.
Hopefully they can also survive over fishing and an unfair big screen rep.