The ancient shark megalodon was not a cold-blooded killer, and that was one thing that caused its extinction.
"Scientists have discovered that the extinct megalodon shark was warm-blooded, as indicated by the isotopes in its tooth enamel. Their research suggests that the megalodon could maintain a body temperature about 13 degrees Fahrenheit warmer than the surrounding water, a significant difference compared to other contemporary sharks".(ScitechDaily.com/Megalodon Was No Cold-Blooded Killer – And That Spelled Its Doom) The ancient shark, known as "megalodon" is one of the largest predators in history. Megalodon was probably a warm-blooded shark. Or actually, megalodon was something, that was a combination of shark and whale. That means the "Meg" was a warm-blooded shark that used gills for breath. The other thing was that megalodon was not more murderous than some tiger sharks. Megalodon was a beast that needed lots of food and it had its place in evolution. But then some other sea predators reach that giant shark. Maybe those new predators like whales ate mega...