During the seventeenth and eighteenth centuries, scientists knew that fossils were the ancient remains of plants and animals. However, most still thought that these fossils represented known, living species that would shortly be discovered living in some remote, unexplored part of the globe.

This changed radically in the 1750s. Explorers in North America found the remains of what they thought were elephants, but in reality the animals were mastodons and mammoths, which died out more than 10,000 years ago toward the end of the Ice Ages. As these and other fossils from the New World were examined, scientists realized the fossils were actually the remains of extinct species. In 1796, Baron Georges Cuvier of the Museum d’Histoire Naturelle in Paris (the first comparative anatomist) published a series of papers proving these “fossil elephants,” and giant mammal bones from other parts of the world, did indeed represent extinct species.