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EmailA Fossil Comes to Life
One of the most important zoological discoveries of the present century gives us a glimpse at the closest living relative of our fish-like ancestors.
The modern coelacanth (Latimeria chalumnae), the closest living relative of our fish-like ancestors
On the twenty-second of last December a trawler dredging in shallow waters off the tip of South Africa brought up in its net a large threshing, biting fish which, because of its size and its unusual appearance, at once attracted the animated and rather cautious attention of the fishing crew. Looking at their curious find with speculative wonder, the fishermen hardly realized their inadvertent discovery of this fish was no less important than if some heat-plagued explorer, fighting his way through an unknown tropical jungle, had suddenly come face to face with a live dinosaur.
This fish was big—over five feet in length, with a weight of 127 pounds; and it was vicious, and, above all, it was quite unlike anything the fishermen had ever seen before. So they took it into East London when they returned to port and presented it as a rather noisome gift to the local Museum. Of course, by the time the fish reached the Museum in East London it was very much defunct, so that the curator, Miss Courtenay-Latimer, had a weighty problem on her hands as to how to preserve such a large zoological specimen with limited facilities.
She sent a communication post-haste to Dr. J. L. B. Smith, a leading South African authority on fishes, asking him to come to see the new animal as soon as possible. But before Doctor Smith could reach East London, the fish was becoming decidedly odoriferous, so Miss Latimer had it skinned, had the skin mounted, saved the skull and disposed of the body.
When Doctor Smith saw the skin, he recognized at once that one of the greatest zoölogical discoveries of the present century lay before him. For what he saw was a living member of a great group of fishes which hitherto had been thought to have become extinct some 60 million years ago. Not only that, this fish belonged to a special group or subclass of the very ancient fishes which included the direct ancestors of all the amphibians, reptiles, birds and mammals. In other words, here was the great-grandchild, to the nth generation, of the brother of our own forebears.
To many people, fishes are fishes and pretty much alike. So that the finding of a specimen so unusual as this new fish from South Africa will not catch the public imagination as much as would a more spectacular and perhaps a more familiar discovery—even of much lesser importance. Yet to those acquainted with fishes, this new find is one of the events of a lifetime—and justly so. For it is a living coelacanth fish (pronounced seé-la-kanth), the likes of which were supposed to have passed from an earthly existence at the time the dinosaurs became extinct.
What are the coelacanth fishes? These are fishes quite distinct from the "ordinary" bony fishes and sharks with which most of us are acquainted. They belong to a separate group or subclass known as the Crossopterygia, or lobe-finned fish, which passed the heyday of their evolutionary history many millions of years ago. The crossopts are distinguished, in short, by a deep body and skull, the skull having a steep "humped" forehead, by two dorsal fins (in contrast with the single dorsal fin of typical fishes), by lobed paired fins, in which the bones show the same positions and relationships as do the bones in the legs and feet of land-living vertebrates, including man himself, and are quite different in structure from the fins of ordinary fish. The coelacanths are also distinguished by a tail having the long axis or backbone running to its tip, by a reduced gill cover or operculum, and by large, heavy scales, the surfaces of which are rugose and covered with enamel. In the extinct coelacanths there was a calcified or partially ossified air-bladder or lung.
A report gained wide acceptance that the fish oozed oil until 20 gallons had escaped, a quantity which would weigh more than the fish itself.
It is unfortunate that the body of this new fish could not be saved, because certain problems as to it internal anatomy, such as the presence of the large lung-like air-bladder, must remain unknown until another specimen can be procured. Meanwhile a false impression should be corrected regarding its capacity for storing oil. A report gained wide acceptance that the fish oozed oil until 20 gallons had escaped, a quantity which would weigh more than the fish itself. The fish exuded 20 ounces of oil, not 20 gallons.