From the Economist obituary of the palaeontologist Richard Fortey.
Trilobites were not only poetry to him. They were also useful. Because he could detect where different species lived, in the open sea or at the shoreline, he could map the ancient edges of continents. It was known that modern continents had split off from a single land-mass; but not that separate continents had existed before that land-mass formed. Through trilobites, like postage stamps, he fixed their positions and remade the prehistoric globe. Proudly, when a fellow-commuter on the 6.21 to Henley asked what he had done that day, he replied that he had moved north Africa 200km to the east. [emphasis added]