Of Megalodons and Leviathan

Years ago, a lumpy package arrived in my mailbox. I noticed my best friend’s return address on it and smiled. Joe sometimes sends me unexpected things. This package qualified: Inside was a dark brown shark’s tooth—five inches long.Joe’s letter explained: It was a fossilized tooth from a prehistoric shark, a megalodon many times bigger than a great white shark. I tried to fathom how big a fish’s jaw would have to be to contain rows of such teeth. Scientists offer a s