Aware that his finding would entirely upend what was understood about the past, and urged by his friend the Reverend William Buckland—he of the gowns and experimental appetite—to proceed with caution, Mantell devoted three painstaking years to seeking evidence to support his conclusions. He sent the tooth to Cuvier in Paris for an opinion, but the great Frenchman dismissed it as being from a hippopotamus. (Cuvier later apologized handsomely for this uncharacteristic error.)
One day while doing research at the Hunterian Museum in London, Mantell fell into conversation with a fellow researcher who told him the tooth looked very like those of animals he had been studying, South American iguanas. A hasty comparison confirmed the resemblance. And so Mantell's creature became Iguanodon, after a basking tropical lizard to which it was not in any manner related.