Peak Fossil

A little while back, my daughter jokingly asked me, “What will you do for a living when they start to run out of fossils to study?”

As is the case for any funny line, there was a grain of truth in that. Fossils can be considered as natural resources, as non-renewable as oil or nickel. Could they ever run out? Could we, in fact, reach peak fossil?

Thinking about this, I realized that peak fossil could refer to several different things. Most obvious is simply the total quantity of fossils in the world. Considered in that sense, there is no danger that we will ever pass peak fossil. Many limestones are composed largely of fossils; smack any random piece of limestone with a hammer, and you have a good chance of breaking a fossil. And there are so many other kinds of fossils: microfossils in deep-sea shales, trace fossils, bones of land vertebrates in sandstones … it is ludicrous to even contemplate that fossils, broadly defined, will never be tremendously plentiful.

Nothing but brachiopods: Ordovician limestone in the Cincinnati area

But what of specific fossils? There are clearly two basic categories of fossils that are sought by people. The first group includes the pretty ammonoids, the rare dinosaur teeth, the spectacular fossil insects, the pieces that are bought, sold, and traded commercially. I am not sure if there is any risk that we will run short of “collector fossils” in general, but it is certainly the case that commercial deposits, like other sorts of mines, can be depleted to the extent that they are no longer viable. Peak fossil may well pass when applied to places like the Baltic amber pits, or some of the sites for Chinese feathered dinosaurs or Moroccan trilobites. And as those deposits are depleted, the dollar values of those fossils will surely rise, just like the values of other “resources.”

Baltic amber pit at Jantarny, Kaliningrad, Russia (Google Maps)

It is the other, final category of fossils that really interests me. This considers fossils as intellectual riches, as data deposits to be mined for new knowledge and ideas. The history of paleontological study could be likened to prospecting for resources. The first great fossil hunt, lasting from about the eighteenth century to the mid twentieth century, sought basic, bulk knowledge. It could be looked at as a drive to understand the diversity of fossils on the planet, which could be applied to other problems such as determining the ages of sedimentary rocks. This was augmented, beginning in the late nineteenth century, by the “dinosaur rush,” which sought big or spectacular fossils suitable for museum exhibit as well as scientific study.

Tyrannosaurus rex, "Sue", on exhibit at the Field Museum, Chicago

In more recent decades, more and more energy has been expended on more and more obscure fossils. The frontiers of paleontological knowledge lie largely near the margins: we are seeking fossils of creatures that do not fossilize under normal conditions, and we are searching for the earliest life forms, the oldest examples of known groups, and the fossils of embryos, cells, or chemicals.

But how much farther can the margins be pushed? Will there be a point beyond which our discoveries will, inevitably diminish? Will we, like the oil companies, expend more and more energy chasing smaller and smaller gains?

I suspect that this could well be the case. The resources committed to the search over the past few decades have allowed us to find some wonderful deposits which have provided considerable new knowledge, but we have not really found another Burgess Shale or another Monte Bolca. I hope that we have not already passed peak fossil; I look forward to reading about the discoveries that prove me wrong.

A beautiful fish fossil from the Monte Bolca (La Galerie de paléontologie et d’anatomie comparée, Paris)

© Graham Young, 2011