We know that megalodon had become extinct by the end of the Pliocene (2.6 million years ago), when the planet entered a phase of global cooling. ... It may also have resulted in the megalodon's prey either going extinct or adapting to the cooler waters and moving to where the sharks could not follow.
What destroyed the megalodon?
The timing is everything. Past research suggests that the megalodon (Otodus megalodon) went missing 2.6 million years ago alongside a wave of marine extinction, potentially caused by a supernova that triggered severe climate and biodiversity changes during this time.
Can the megalodon still be alive?
Megalodon is NOT alive today, it went extinct around 3.5 million years ago. Go to the Megalodon Shark Page to learn the real facts about the largest shark to ever live, including the actual research about it's extinction.