NOVA: Sharks have an endless supply of teeth ... Some people are almost insensitive to pain, others are highly sensitive. I have done minor surgery on sharks, and they seem not to feel it.

Shark teeth are especially valuable for this purpose. Their abundance and durability make them a treasure trove of information about past environments. However, uncovering patterns in ancient ...

bringing an end to shark trophy hunting charters, taking baby sharks for the aquarium pet trade and the intentional killing or mutilation of sharks for their teeth, jaws or other parts.