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

Because we haven’t found a tooth fossil that was less than several million years old. The fossils we do have are of teeth because that’s the only part of the megalodon (and most sharks) that is capable of fossilization. The only thing that could have stopped the fossiliation of newer megalodon teeth without impacting the fossil record of other animals would be a lack of megalodon teeth to fossilize.

Similarly, we discovered giant squid because we kept finding their bodies, the first one was found in 1880, but it was only a 2004 we first saw a live one.