Ancient sharks became extinct 2.6 million years ago
Features Monday, October 27, 2014 - 05:30
The News Minute| October 26, 2014| 11.50 pm IST By analysing dozens of Megalodon fossils, researchers estimated that the ancient shark, the largest to ever live, is likely to have gone extinct about 2.6 million years ago. While researchers are still not clear as to why these giant, 60-foot-long sharks (Carcharocles megalodon) went extinct, scientists now have a better estimate for when it happened. "We get 10,000 estimates for the time the species went extinct and then we look at the distribution of those estimates through time," Live Science quoted Chris Clements, research assistant at the University of Zurich, as saying. The team used the Optimal Linear Estimation (OLE) technique to estimate when the Megalodon became extinct. "Though the technique does not give us the exact date when a species went extinct, it gives the date by which, it can be assumed that a species has gone extinct," Clements added. They identified 42 of the most recent fossils after sorting through the Paleobiology Database - a large, online compilation of fossil data. Each of the 42 fossils were entered into the database, with an upper and lower date estimate for when it appeared. The researchers then ran 10,000 simulations and each simulation selected a date for the said fossils, somewhere, between the upper and lower boundary. This date falls on the border between the Pliocene and Pleistocene epochs, from the time when baleen whales began growing to their modern-day gigantic sizes. Most Megalodon fossils date back to the middle Miocene Epoch (15.9 million to 11.6 million years ago) and the Pliocene Epoch (5.3 million to 2.6 million years ago). The timing of the Megalodon's extinction makes sense, since these ancient sharks fed on marine mammals, including whales and dolphins, the researchers said. Picture by Karen Carr. IANS
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