In December 1938, fishermen off the east coast of South Africa pulled up a strange-looking fish. It was five feet long and pale blue, with an unusually large, lobed tail. The fishermen gave the fish to Marjorie Courtenay-Latimer, the curator of a local museum. She had never seen anything like it, so she sent a sketch to Professor J. L. B. Smith, a fish expert. When he saw the drawing, he was astounded.

It looked almost exactly like the coelacanth, a fish thought to have died out about sixty-five million years earlier. How could this fish, missing from the fossil record for tens of millions of years, still be swimming in the ocean? Why had it survived when so many other species had become extinct? What could it reveal about life in prehistoric times? The fish appeared to be a "living fossil.".