The huge fossil teeth of megalodon had been known for centuries and were once believed to be the fossilized tongues of dragons. Agassiz, noting that great white shark teeth and the fossil megalodon teeth were both serrated, lumped megalodon into the same genus, Carcharodon, (from the Greek karcharos, meaning sharp or jagged, and odous, meaning tooth).

Agassiz was not, however, making an evolutionary judgment. In 1835, a young Charles Darwin was just then visiting the Galapagos Islands. There would be no theory of evolutionary descent for nearly 25 years. In fact, the brilliant Agassiz, who later became a professor at Harvard and the leading figure of natural history in the United States, forever resisted Darwin’s revolutionary ideas. Rejecting biological evolution, Agassiz defined species as a “thought of God.” His classification scheme signified nothing about shark origins.

But over the next century, the idea that great whites evolved from megalodon took hold. <<

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