The Great Fossil Enigma (24 page)

Other studies were taking place in West Germany, Willi Ziegler having moved to the Geological Survey at Krefeld near Dusseldorf in 1958. Here he began work on his “habilitation” thesis at the University of Bonn, which would permit him to practice as a university academic. It was here that the conodont started to become an essential part of his being and where he would become the ultimate conodont specialist and outcompete his compatriots. Ziegler had already demonstrated evolutionary trends in a number of conodont genera in the late 1950s, including
Palmatolepis.
In his thesis, completed in 1962, he took this work several stages further and produced a high-resolution conodont zonation for the Upper Devonian in its entirety. Based on a study of encyclopedic magnitude in which vast numbers of samples were taken at ten-centimeter intervals, his twenty-four zones and zone divisions challenged the supremacy and current orthodoxy of cephalopod zones. The reward for this herculean effort was the production of a continuous temporal landscape upon which he could plot the trajectories of conodont evolution at its most plastic and eventful. Ziegler was convinced that he now possessed the universal timescale, reassured by tests he carried out in other parts of Europe.
¹¹
It was a realization of what so many had imagined at Dillenburg less than a decade before.

7.1.
Helms's iconic representation of the evolutionary development of
Palmatolepis
, “the best of all fossils for the subdivision of the Upper Devonian,” published in the 1962
Treatise.
Ziegler joined Helms in maintaining its accuracy. Time runs vertically, from bottom to top, in this diagram. Reproduced with permission from K. J. Müller,
Treatise on Invertebrate Paleontology
, Part W Miscellanea (1962). Courtesy of and ©1962, The Geological Society of America and The University of Kansas.

Like Helms, Ziegler found parent forms like
Palmatolepis triangularis
highly variable. Both agreed that this fossil was the rootstock of all successive
Palmatolepis
species. The rapid evolution of
Palmatolepis
was one of the keys to Ziegler's timescale and it gave up its evolutionary secrets rather easily, as did
Spathognathodus.
Ziegler could see change gradually occurring as one species became another as different features were reshaped and resized. He could also detect long-term trends, such as a reduction of surface area and a sigmoidal buckling, which occurred in numerous branches of the evolutionary tree.

However, before Ziegler could publish his results, Helms stole a little of his thunder by giving Müller a diagram showing the results of his own investigations, which Müller added to the
Treatise
, then in the final stages of its publication (
figure 7.1
). Essentially communicating much of the story Ziegler had also unraveled, Helms's pictorial representation of conodont evolution became an icon for the new science; it would not be surpassed. However, when Helms came to give explanation to this diagram in 1963, he corroborated Ziegler's own interpretations, which had by then been published. Built upon friendly cooperation with Ziegler, and riding the wave of this upsurge in German stratigraphy, Helms celebrated the conodonts' survival in large numbers and their preservation of ontogeny and evolution; they seemed to challenge all other fossils for the stratigraphic crown.
¹²

Helms was, however, aware that his diagram showed the evolution of an anatomical part of an animal, not of the animal itself. This was not unusual in paleontology; specialists in fossil mammals, for example, frequently had nothing more than teeth to go on. Of course, this kind of focus was an easy target. As Stephen Jay Gould later remarked, “An old paleontological in joke proclaims that mammalian evolution is a tale told by teeth mating to produce slightly altered descendant teeth.”
¹³
Helms held no such simplistic beliefs. Unconvinced by the universality of his conclusions and aware that a two-dimensional diagram could not capture the complexity of change, he presented that change in prose. Here he discussed the emergence of features, moments of rapid change and periods of character stabilization, in which variable ancestral populations gave rise to distinctive forms.

Ziegler soon overtook Helms in this race for global domination, and it relied not only on the quality of his scientific work, his sheer hard work, and his unparalleled passion for this fossil, but also on his unbridled evangelical zeal. In the autumn of 1961, he visited the United States, where he lectured to Bill Furnish's and Brian Glenister's graduate students at the University of Iowa. Gil Klapper, then a doctoral student working on the Devonian-Mississippian boundary, recalls a field trip to Campbell's Run led by Furnish. With Ziegler's encouragement, Furnish and Klapper took three samples from a measured section of the Sweetland Creek Shale found there. Returning to the university, they processed and sorted this material while Ziegler examined the Geology Department's type fossils. To their amazement, they found three of Ziegler's zones. After Ziegler left to visit other collections and other workers, Klapper and Furnish returned to the section to do a more thorough job and found five of Ziegler's zones. These results, when published in 1963, were a critical breakthrough for Ziegler's global ambitions.
¹⁴

The next major step came a few years later, when Brian Glenister found conodonts in the matrix of cephalopod fossils from the Canning Basin in Australia. Glenister had worked on cephalopods for Western Australian Petroleum (
WAPET
) back in the 1950s, at a time when these cephalopods were used for international correlation. He passed the conodonts on to Klapper, who then drew upon Ziegler's resources in Krefeld to interpret them. He again found Ziegler's zones. However, when Glenister and Klapper brought this discovery to publication, rather than follow Ziegler's system, thereby assuring it of the status of a global standard, they replaced his names with numbers. This caused Ziegler considerable distress, which became all the more amplified when David Clark adopted the same scheme in a study of the Great Basin.
¹⁵
It was, however, a temporary blip, though, as we shall see, it was not the only one to disturb Ziegler's perfect system in the mid- to late 1960s.

The final stage in the conodonts' emergence from obscurity occurred late in the summer of love, September 1967, at an international meeting in Calgary organized to discuss the Devonian. To the surprise and delight of Huddle and others who were there, “paleontologists working on other fossils deferred to conodont age determinations.” Klapper recalled this moment as a “historical watershed.” The conodont had proven itself on a global scale and overcome any residual fears that faunas might be contaminated or mixed and therefore unreliable.
¹⁶
Buoyed up by this recognition, Klaus Müller, Larry Rickard, and John Huddle alighted upon the idea of a society – which was then discussed by twentyfive conodont workers at the end of the conference. On the strength of his seniority, Huddle found himself unanimously elected “president,” an office soon to be labeled “Chief Panderer.” Charlie Collinson suggested the society's name – the Pander Society – which by the time of the second meeting had raised a few eyebrows (in the United States, “pander” has the “somewhat unsavory meaning” of “pimp”). The society that emerged from this seventy-minute discussion became the research hub for the science. Its membership grew organically and rapidly, its annual newsletter recording little more than a catalogue of publications and meetings, as well as a list of members and their interests: “The ‘Pander Society' is informal. It has no constitution, bylaws, or rules and
NO DUES.”
¹⁷
The society reveled in being as enigmatic as its subject matter and claimed that any meeting of three or more conodont specialists could be termed a “Pander Society meeting.” Undoubtedly an informal association, the group nevertheless got down to business and in a series of thematic international meetings it tackled the long list of unknowns and concerns that conodont workers shared. There can be little doubt that, with the entry of the fossil into mainstream science, 1967 marked a point of culmination. It also marked a step change in the science's socialization. The new society became a dynamo and catalyst, providing an informed and critical specialist audience, all of which would serve to accelerate the rate of progress. Buoyed up by a new commonality of purpose, which produced shared agenda and a world resource of data, conodont studies entered a new era.

But soon the American-led Pander Society discovered it was not alone; a Soviet group, known as Pander's Grandchildren, had also recently been inaugurated. Indian and other national groups would emerge in the future as momentum grew and the full implications of the globalization of science were felt. By 1972 the Pander Society had a membership of 250 from thirty-one countries.
¹⁸

Ziegler's global ambitions for his Upper Devonian conodont zones were pretty much achieved by the end of the 1960s, and by the time he returned to Marburg in 1969, even the troubling Lower Devonian seemed to be coming under his control. He now became a key participant in those international organizations, that sought to establish global standards for the Devonian.
¹⁹
And he also began work compiling the massive and, to his mind, definitive
Catalogue of Conodonts
, a description of every known species.

Although most geologists saw in Ziegler's and Helms's work a more refined means to order rocks, these authors' insights relied entirely on earlier prophesies that the key to understanding this animal – at least as an abstract thing – lay in unraveling its evolution. In this, Ziegler was simply the most successful of a generation of workers who attempted to map every root and branch of the conodonts' family tree. Looked at from a distance, this tree suggested that these fossils showed an evolutionary tendency toward increased surface area. Cones had developed into blades and bars, and these into platforms. This had not, however, taken place as stages on a linear journey, but, as Müller revealed, by different means and along different branches of the family tree.
²⁰

Müller mapped that tree in 1962. By then he had already began his journey backward along that path – marked by a dashed line in his diagram – which took him beyond the Ordovician and into the Cambrian, toward the point of origin of the conodonts. He began that journey on his sabbatical at the University of Iowa in the summer of 1955. Here Furnish had found conodonts low down in the Ordovician. Müller went in search of still older Cambrian forms in the Arbuckle Mountains of south-central Oklahoma, but these too proved to be Ordovician. So he turned his attention to the Deadwood Formation of the Black Hills of South Dakota, rocks that had interested the Iowa workers for some time.
²¹
Using acids on limestones lying below a proven Upper Cambrian shale, Müller at last found his quarry. These conodonts were entirely new, very distinctive, and quite unlike any seen in the Ordovician.

Through a comparison of material from Germany, Wyoming, and Utah, he could be sure the rocks in which he had found these fossils were Cambrian in age. Then he began to wonder if these strange fossils really were conodonts, but Furnish reassured him. Regaining his confidence and projecting his knowledge of conodont evolution backward into the void of the unknown, Müller thought his new fossils fitted the bill of conodont ancestors pretty well. They were all simple forms with large basal cavities.