Rumors of dinosaurs, sea serpents and other weird creatures being sighted in remote corners of the globe crop up frequently in media reports. No one can squelch the hope that such discoveries will actually take place and that dinosaurs are still clinging to life on some unexplored island.
Occasionally we read a report of a scientist describing an animal or plant that is a living remnant of a long gone era; such an organism is referred to as a "living fossil." It is an animal or plant from a species that has survived long past the era in which it flourished. Usually the survivor has changed very little in appearance from its remote ancestors, so the name "living fossils" seems appropriate even though the words "living" and "fossil" contradict each other.What truly captures the attention of the public in regard to living fossils is the discovery of a living animal whose species has been thought to have been completely extinct for millions of years. Such a creature was discovered by a fisherman in 1938. While retrieving his heavily laden fish nets at the mouth of the Chalumna River in South Africa, the man was surprised to find a strange looking fish flopping around among the ordinary fish in the net. It measured over five feet in length and topped 110 pounds. The strange appearance of this creature caused him to turn it over to Marjorie Latimer, the curator of the museum at East London, South Africa.
She too was fascinated by the appearance of the fish, for she had never seen one like it before, nor was she familiar with any fish of its description. She immediately wrote to J.L.B. Smith, the leading fish expert in South Africa. He informed her he would be there after the Christmas holidays more than a week later. As it began to decay, Latimer gutted the fish and threw the valuable entrails away, and a taxidermist stuffed the creature.
When Smith finally arrived, the now mounted fish was presented to him. At first glance he was simply transfixed; his astonishment knew no bounds, for he recognized a creature that was believed to have vanished completely from the face of the earth some 70 million years ago. This was a Coelacanth, a type of Crossopterygi, or lobe-finned fish. No run-of-the-mill fish even then, it was a member of the Crossopterygian Order that had crawled out of the waters on its lobefins to become the first land-dwelling vertebrate, about 400 million years ago.
The professor considered the loss of internal organs catastrophic for his study but reasoned, correctly, that others would be found. He honored Latimer by naming the fish Latimeria chalumnae. Fourteen years later, Smith's prediction came true. Another fish was caught off the Comoro Islands, between the east coast of Africa and Madagascar.
Unfortunately, news released to the media with the discovery of the Coelacanth identified it as the lobe-finned ancestor of amphibians that walked out of the water and on to the mud. Then followed the reptiles, birds and mammals, making the Coelacanth the ancestor of all land dwelling vertebrates. Although this fish was a member of the order Crossopterygi, the Latimeria is only a cousin, many eons removed from the fish of the fossil record. Remarkably, this specimen of Coelacanth had changed little in its outward appearance over these 300 million years. Its body plan is primitive, generalized and adaptable, so no change has been obvious enough to keep us from recognizing the kinship of this living species with its fossil ancestor.
No fossil forms of the Coelacanth have been found in rocks younger than 65 million years, and so it seemed safe to assume from this negative evidence that they had become completely extinct at the end of the Cretaceous Period. The discovery in 1938 shows that somehow the Coelacanth managed to persist, and the search for some record to fill the 65 million year gap must continue.
Since 1952 about 170 specimens have been captured or photographed, all in around the volcanic slopes of the Comoro Islands. Natives of these islands informed the scientists that before the 1938 discovery, which attracted the attention of the world beyond the Comoros, Coelacanths had been caught occasionally by local fishermen. They were not everyone's favorite fruit of the sea, being palatable only when salted and dried. Their scales were discovered to be better than sandpaper for scratching bicycles tires before applying a patch. One can then assume that many a scientific treasure has either gone into the cooking pot or the toolbox.
Their relative scarcity seems to indicate that they may now be on the verge of extinction. Or perhaps they have found their place on the planet: slightly cool, slightly dark, slightly deep (300 to 1,500 feet), somewhat sterile, so competition is minimal. Their food supply will also be meager, so the population should be limited. Fresh volcanic rock of the Comoros may provide the trace metals they favor. As the volcanic islands are built up and eroded away -- give or take another million years -- they may discover another place more amenable to their needs, or a new way to adapt. The Coelacanth did not survive for 400 million years without learning how to change along with an ever-changing Earth.
Phil and Nancy Seff are the authors of several science books, including "Our Fascinating Earth." Their column runs regularly in the Deseret News Science/Technology section.