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