How are scientists certain that Megalodon is extinct when approximately 95% of the world’s oceans remain unexplored?

Question

Would like to understand the scientific understanding that can be simply conveyed.

Thanks you.

In: 5134

Answer 1

Imagine an invisible Tyrannosaurus Rex that lives in the depths of the Amazon rain forest. Set up a thousand trail cameras and you still only cover 1% off the possible space. But we don’t find poop, we don’t find hunting trails, we don’t find the clearings and sprouts of growth where large animals die, and none of the local prey animals have learned to hide high in the canopy or below the ground at the slightest vibration.

We’d have to search the entire rain forest to be 100% sure; but without any of the signs that normally indicate a large predator, we’re 99.9999% sure that Rainforest Rex is extinct.