The Fossil Souk

The trilobite looks like a stone horseshoe crab, curled into a defensive ball. It has compound eyes made of calcite — some of the earliest visual systems on earth — and a segmented body that flexed when predators approached. It swam in the shallow seas that covered Morocco 400 million years ago, during the Devonian period, when fish were just beginning to crawl onto land and everything was still figuring out what it wanted to be.

Now it sits on a dusty shelf in Erfoud, priced at 800 dirhams.

The town at the edge of the Sahara is the fossil capital of Morocco, possibly the world. During the Devonian, this was the floor of a prehistoric ocean. When the water receded, it left behind a geological record so dense that farmers still plough up trilobites in their fields — the way farmers elsewhere turn up potatoes, except with slightly more scientific significance. More than 50,000 Moroccans earn their living in the fossil trade: mining, preparing, exporting. The industry is worth over $40 million annually, which makes it one of the more successful posthumous careers in natural history.

The fossils include hundreds of trilobite species, many found nowhere else on earth. Some have elaborate spines and horns that suggest the Devonian was not a relaxing time to be alive. Some are the size of a fingernail; others span a forearm. There are orthoceras — extinct squid relatives preserved in black limestone, their conical shells stacked like organ pipes. There are ammonites, the spiral-shelled ancestors of the octopus. There are sea lilies and ancient corals and, occasionally, the teeth of Devonian sharks, which had the same approach to dentistry as modern sharks and roughly the same temperament.

The preparation is an art. Workers extract fossils from limestone using pneumatic tools, then spend hours — sometimes days — with dental picks and brushes, exposing every spine and segment with the patience of surgeons and the pay of not-surgeons. The best specimens end up in natural history museums from London to New York. The rest fill the fossil shops that line Erfoud's main street, where tourists bargain over coffee tables inlaid with polished orthoceras and bathroom sinks carved from ammonite marble. There is something wonderfully absurd about washing your hands over a creature that died before trees existed.

Louis Gentil, the French geologist, discovered trilobites near Casablanca in 1916. But the explosion came in the 1980s and 1990s, when fossil collecting became a global hobby. Suddenly there was a market for creatures that had been lying in Moroccan rock for eons, waiting — without knowing they were waiting — to be rediscovered and sold to a dentist in Stuttgart.

Some worry about what's being lost. The fossil beds around Erfoud have been called the largest open-air fossil museum in the world, but they're being excavated faster than scientists can study them. Forgeries appear: composites of multiple specimens, or creatures enhanced with creative additions that would have surprised the original owner. Yet without the market, palaeontologists acknowledge, many species would never have been found at all. The fossil trade is destruction and discovery in the same pick stroke.

The irony is beautiful. The Sahara — the driest place on the continent — preserves the record of an ancient ocean. Four hundred million years of evolution, compressed into stone, arranged on shelves, waiting for someone to take it home.