Why the Meg is Extinct
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. Precisely when the last megalodon died is not known, but new evidence suggests that it was at least 3.6 million years ago. Scientists think that up to a third of all large marine animals, including 43% of turtles and 35% of sea birds, became extinct as temperatures cooled and the number of organisms at the base of the food chain plummeted, resulting in a knock-on effect to the predators at the top. The cooling of the planet may have contributed to the extinction of the megalodon in a number of ways. As the adult sharks were dependent on tropical waters, the drop in ocean temperatures likely resulted in a significant loss of habitat. 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. Megalodon is also thought to have given birth to its young close to the shore. These shallow coastal waters would have provided a nursery for the pups, protecting them from predators that were lurking in the open water, like the larger toothed whales. As ice formed at the poles and the sea level dropped, these pupping grounds would have been destroyed. A study from 2022 suggests that competition with great white sharks for food may also have contributed to megalodon's downfall. Studies of fossilised megalodon and great white teeth show that their diets overlapped.