Spiky-Headed Sharks Survived Mass Extinction, Surprising Scientists
An exotic, ancient shark thrived into the age of dinosaurs, study says.
by Dan Vergano
A family of small sharks—some of which had spiky heads—cruised the ancient seas for far longer than scientists had suspected, surviving to about 120 million years ago. Their surprising survival suggests that deep oceans sheltered predators during past mass extinctions.
Some 252 million years ago, roughly 90 percent of the planet’s marine species perished in the Permian-Triassic mass extinction event.
Tied to everything from volcanic eruptions to ocean oxygen depletion to severe climate change, the Great Dying represents the most severe challenge to life’s survival seen in the fossil record…
(read more: National Geo)
illustration by Alain Beneteau, 2013