Search engines: Serendipity - A living, breathing fossil

LAST WEEK I was reading A Fish Caught in Time, Samantha Weinberg's recently published account of the discovery of the coelacanth, when I came across a beautiful example of serendipity. Biologists had long been aware of the coelacanth from fossils dating back to between 70 and 400 million years, but they were shocked when a living, breathing specimen was discovered in 1938, entangled in the nets of a South African fishing boat. This was in itself a serendipitous event, but there was an equally fortuitous discovery some years later, which became a major turning point in the story of the coelacanth.

The 1938 fossil-fish belonged to a thriving colony of coelacanths living off the Comoros Islands, between Madagascar and Mozambique. Evolutionary biologists were overjoyed that this community had survived, because coelacanths have limb- like fins, and offer an insight into the moment in history when marine life began to colonise the land, when fishes evolved into creatures with legs.

It seemed like a miracle that these archaic organisms had survived the mass extinction that wiped out the dinosaurs. So, there was a general sense of astonishment in 1964 when Dr Ladislao Reti, an Argentinian chemist, accidentally discovered evidence hinting at the existence of another colony. He spotted a silver fish ornament in a church near Bilbao, Spain. The limb-like fins, the peculiar skull and the puppy-dog tail clearly indicated that this was a model of a coelacanth, and initially it seemed as if the 10cm ornament was an attempt to cash in on the coelacanth mania that gripped the world. However, silver experts claimed that the fish was 200 years old and had been brought to Spain from Central America.

One explanation was that the silversmith had modelled the fish on fossils, but this seemed unlikely because of the level of detail on the ornament. In particular, the ornament had engravings on the scales that represented the white flecks found on the Comoros coelacanths. Such a detail could not have been discerned from a fossil. A more plausible explanation was that the silversmith worked from a real specimen, which meant that there must be a colony in the New World, perhaps in the Gulf of Mexico. Thereafter, biologists began to search for other coelacanth colonies. If they lived off East Africa and off Central America, then perhaps they lived all over the world, hidden away in the deepest reaches of the oceans.

In 1997, Mark Erdmann, a marine biologist, and Arnaz Mehta were married on Bali. They honeymooned on the Indonesian island of Manado, and while touring a local fish market they spied a coelacanth. Erdmann recognised the creature, and the couple went on to locate the Indonesian colony. As yet, the New World colony remains undiscovered.

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