Whatever Killed the Dinosaurs Also Jumbled Shark Evolution

More than 500 different shark species roam Earth’s oceans, from zippy little cookie-cutter sharks...
to the iconic great white, to goblin sharks, to 25-foot-long, filter-feeding basking sharks.
And it seems that the current equilibrium of shark species we see today arose after...
the Cretaceous–Paleogene mass extinction event 66 million years ago says new research.
In the Cretaceous Period, an order of Lamniform sharks like the great white, thresher, and mako owned the seas.