The Great Fossil Enigma: The Search for the Conodont Animal

13: El Dorado

293 293 El Dorado For those who went in search of Pander’s El Dorado, that distant city of gold was where the extinct mythological beast lay at rest, its flesh sufficiently preserved to at last reveal the truth.1 In 1923, Macfarlane had dreamed of such a place, “that some layer of subaquatic volcanic ash may yet be discovered.” Many had dreamed, but the animal had not revealed itself. Few, if anyone, had imagined that this sacred place might be a shelf, box, package or drawer. But there it was, this Holy Grail of science. And there it had been for some sixty years. Hidden from view and beyond the reach of all earlier attempts to find it, it might just as well have been lost in the mountainous jungles of Guyana. Then, in 1982, Euan Clarkson found it–though at first he did not know precisely what he had found. A paleontologist at the University of Edinburgh, he had been searching for fossil shrimps in the Granton Shrimp Bed. This rock outcrops where that city meets the sea, but Clarkson was not bravingtheScottishweather .Hewasworkinghiswaythrougholdcollections held by the British Geological Survey in Edinburgh, much of which had been collected by the Survey’s fossil collector, David Tait, early in the twentieth century. A shrimp bed had been first discovered at Cheese Bay in East Lothian , some twenty-five miles from Edinburgh, in 1903, but was soon exhaustedasaresultoftheattentionpaidtoitbycollectorsandtheSurvey ’s paleontologists. It contained a single kind of shrimp but no other fossils . Collectors then made their way along the coast in search of further outcrops. In 1917, Tait at last found one: a finely laminated limestone, forty-five centimeters thick, in a coastal section dominated by Carbonthirteen 294 The Great Fossil Enigma iferous black shales. The limestone was unique and quite different from that at Cheese Bay, for despite its considerable age, it preserved the soft and delicate structures of shrimps, worms, and a host of other animals.2 Tait gathered up small slabs of this precious rock and placed them into the protective care of the Survey, there to serve science as and when they were needed. At that moment, of course, on the other side of the Atlantic, Edward Kindle, E. O. Ulrich, and the others were just beginning to believe that the conodont might resolve the dispute over the black shales–rocks roughlycontemporarywiththoseatGranton.Butin1919,thosethoughts were still immature and micropaleontology itself a thing of the future. Ulrich and Ray Bassler had not then split the conodonts into a myriad different fishes, nor had they or Ted Branson and Maurice Mehl proven their utility. For Tait, working in the practical world of Survey geology, the conodont lay beyond his field of vision. Among all those smudgy suggestions of life, the tiny animal was in so many ways invisible. • • • Clarkson lived in a different world. He belonged to that postwar generation that had aspired to a new paleontology and in recent decades had gained a new optimism following the discovery that Lagerstätten were not as rare as previously thought. A science built largely on the evidence of bones and shells, these remarkable deposits provided “windows ” through which lost worlds could be seen in all their ecological and anatomical glory. They made it possible to both imagine a deep past clothed in flesh and aspire to the invention of that long desired science of palaeobiology. Among those who had pioneered this new vision was Clarkson’s collaborator in the shrimp project, Derek Briggs, a paleontologist at Goldsmith’s College in London. In the 1970s, Briggs and Simon Conway Morris had been part of a three-man research team, led by Harry Whittington, that re-examined the oldest and most extraordinary Lagerst ätte then known, the Burgess Shale of British Columbia in Canada. Using the evidence of rare and fragmentary fossils, they conjured up a previously unimaginable world, for the rocks seemed to record a great El Dorado 295 biological experiment that had taken place at that very moment when life had acquired its anatomical complexity. The old orthodoxy, which they were now displacing, suggested that life had been born into a number of biological groups (mollusks, echinoderms, annelids, etc.) that persisted through the millennia. Animals had continued to evolve, but they had done so within the constraints of this natural order. It was this knowledge that encouraged paleontologists to pigeonhole their finds and believe that all life must...