New research suggests that one mysterious event nearly wiped out the shark population nearly 19 million years ago. Because scientists in the new study looked at shark teeth buried in deep-sea sediments, shark diversity today is only a fraction of the much greater diversity that existed at the time.
They say this unidentified large-scale marine extinction has reduced shark diversity by more than 70% and almost completely lost their entire population. Scientists say the reason for this event remains a mystery. The researchers say one event nearly removed sharks from pelagic sediments, cutting the population by nearly 90%.
They added that the sudden disappearance is not associated with any known global climate change. A research report published in the journal Science showed that modern sharks began to differ from endangered sharks from 2 to 5 million years ago, but this is only a small fraction of their predecessors.
The Science Report cites Elizabeth Siebert, Ph.D. Student at the Yale University Institute for Biosphere Research and co-author of the study. They have survived many mass extinctions.
“Siebert said the discovery was led by studies on other microfossils and relatively rare microfossils smaller than shark scales found in most sediment types,” Siebert told WordsSideKick. Get your doctorate.
“Early in my career as a scientist, I decided what to do with these fossils and what questions to ask about them,” Siebert said. For the new study, Cybele and Rhea Rubin are co-authors of Atlantic College in Bar Harbor, Maine.