The Best American Science and Nature Writing 2014

by Deborah Blum

Tassy opened one of the metal cabinets and placed its contents on a wooden table. These were some of the mastodon teeth that Cuvier had handled. The teeth had been found in the Ohio River Valley in 1739 by French soldiers, and, though they were there to fight a war, the soldiers had lugged the teeth down the Mississippi and put them on a boat to Paris.

  “This is the Mona Lisa of paleontology,” Tassy said, pointing to the largest of the group. “The beginning of everything. It’s incredible, because Cuvier himself made the drawing of this tooth. So he looked at it very carefully.” I picked it up in both hands. It was indeed a remarkable object. It was around 8 inches long and 4 across—about the size of a brick, and nearly as heavy. The cusps—four sets—were pointy, and the enamel was still largely intact. The roots, as thick as ropes, formed a solid mass the color of mahogany.

  What particularly intrigued Cuvier about the mastodon teeth—and perplexed his predecessors—was that although they’d been found alongside a giant tusk, they didn’t look anything like elephant teeth. Instead, they looked as though they could have belonged to an enormous human. (A mastodon molar that was sent to London in another eighteenth-century shipment was labeled “Tooth of a Giant.”) In evolutionary terms, the explanation for this is simple: about 30 million years ago, the proboscidean line that would lead to mastodons split off from the line that would lead to elephants and also mammoths. The latter would eventually develop its more sophisticated teeth, which have ridges on the surface rather than cusps. (This arrangement is a lot tougher, and it allows elephants—and used to allow mammoths—to consume an unusually abrasive diet.)

  Mastodons, meanwhile, retained their relatively primitive molars (as did humans) and just kept chomping away. Of course, as Tassy pointed out, the evolutionary perspective is precisely what Cuvier lacked, which in some ways makes his achievements that much more impressive.

  “Sure, he made errors,” Tassy said. “But his technical works—most of them are splendid. He was a real fantastic anatomist.”

  After we had examined the teeth a while longer, Tassy took me up to the paleontology hall. Just beyond the entrance, a giant femur, also sent from the Ohio River Valley to Paris, was displayed, mounted on a pedestal. It was as wide around as a fence post. French schoolchildren were streaming past us, yelling excitedly. Tassy had a large ring of keys, which he used to open various drawers underneath the glass display cases. He showed me a mammoth tooth that had been examined by Cuvier, and bits of various other extinct species that Cuvier had been the first to identify. Then we looked at one of the world’s most famous fossils, known as the Maastricht animal—an enormous pointy jaw studded with sharklike teeth. In the eighteenth century, the Maastricht fossil was thought by some to belong to a strange crocodile and by others to be from a snaggletoothed whale. Cuvier attributed it, yet again correctly, to a marine reptile. (The creature was later dubbed a mosasaur.)

  Around lunchtime, I walked Tassy back to his office and then wandered through the gardens to the restaurant next to Cuvier’s old house. Because it seemed like the thing to do, I ordered the Menu Cuvier—your choice of entrée plus dessert. As I was working my way through the second course—a cream-filled tart—I began to feel uncomfortably full. I was reminded of a description I had read of the anatomist’s anatomy. During the revolution, Cuvier was thin. In the years he lived on the museum grounds, he grew stouter and stouter until, toward the end of his life, he became enormously fat.

  With his lecture on “the species of elephants, both living and fossil,” Cuvier had succeeded in establishing extinction as a fact. But his most extravagant assertion—that there had existed a whole lost world, filled with lost species—remained just that. If there had indeed been such a world, then it ought to be possible to find traces of other extinct animals. So Cuvier set out to find them.

  Paris in the 1790s was a fine place to be a paleontologist. The hills to the north of the city were riddled with quarries that were actively producing gypsum, the main ingredient of plaster of Paris. (The capital grew so quickly over so many mines that cave-ins were a major concern.) Not infrequently, quarriers came upon weird bones, which were prized by collectors even though they had no real idea what they were collecting. With the help of one such enthusiast, Cuvier soon assembled the pieces of another extinct animal, which he described as l’animal moyen de Montmartre—“the medium-sized animal from Montmartre.”

  By 1800, four years after the elephant paper, Cuvier’s fossil zoo had expanded to include twenty-three species that he deemed to be extinct. Among these were a pygmy hippopotamus, whose remains he found in a storeroom at the Paris museum; an elk with enormous antlers, whose bones had been found in Ireland; and a large bear—what now would be known as a cave bear—from Germany. The Montmartre animal had, by this point, divided, or multiplied, into six separate species. (Even today, little is known about these species except that they were ungulates and lived some 30 to 40 million years ago.) “If so many lost species have been restored in so little time, how many must be supposed to exist still in the depths of the earth?” Cuvier asked.

  Cuvier had a showman’s flair and, long before the museum employed public relations professionals, knew how to grab attention. (“He was a man who could have been a star on television today,” Tassy told me.) At one point, the gypsum quarries around Paris yielded a fossil of a rabbit-size creature with a narrow body and a squarish head. Cuvier hypothesized, based on the shape of its teeth, that the fossil belonged to a marsupial. This was a bold claim, as there were no known marsupials in the Old World. To heighten the drama, Cuvier announced that he would put his identification to a public test. Marsupials have a distinctive pair of bones, now known as epipubic bones, that extend from their pelvis. Though these bones were not visible in the fossil as it was presented to Cuvier, he predicted that if he scratched around, the missing bones would be revealed. He invited Paris’s scientific elite to gather and watch as he picked away at the fossil with a fine needle. Voilà, the bones appeared. (A cast of the marsupial fossil is on display in Paris in the paleontology hall, but the original is deemed too valuable to be exhibited and is kept in a special vault.)

  Cuvier staged a similar bit of paleontological performance art during a trip to the Netherlands. In a museum in Haarlem, he examined a specimen that consisted of a large semicircular skull attached to part of a spinal column. The fossil, three feet long, had been discovered nearly a century earlier and had been attributed—rather curiously, given the shape of the head—to a human. (It had even been assigned a scientific name: Homo diluvii testis, or “man who was witness to the Flood.”) To rebut this identification, Cuvier first found an ordinary salamander skeleton. Then, as Rudwick relates it, he began chipping away at the rock around the deluge man’s spine. When he uncovered the fossil animal’s forelimbs, they were, just as he had predicted, shaped like a salamander’s. The creature was not an antediluvian human but something far weirder: a giant amphibian.

  The more extinct species Cuvier turned up, the more the nature of the beasts seemed to change. Cave bears, giant sloths, even giant salamanders—all these bore some relation to species that were still alive. But what to make of a bizarre fossil that had been found in a limestone formation in Bavaria? Cuvier received an engraving of this fossil from one of his many correspondents. It showed a tangle of bones, including what looked to be extremely long arms, skinny fingers, and a narrow beak. The first naturalist to examine it speculated that its owner had been a sea animal and had used its elongated arms as paddles. Cuvier, on the basis of the engraving, determined—shockingly—that the animal was actually a flying reptile. He called it a ptero-dactyle, meaning “wing-fingered.”

  Cuvier’s proof of extinction—of “a world previous to ours”—was a sensational event, and news of it soon spread across the Atlantic. When a nearly complete giant skeleton was unearthed by some farm hands in Newburgh, New York, it was recognized as a find of great significance. Vice President Thomas Jefferson made several attempts to get his hands o
n the bones. He failed. But a friend, the artist Charles Willson Peale, who’d recently established the nation’s first natural history museum, in Philadelphia, succeeded.

  Peale, perhaps an even more accomplished showman than Cuvier, spent months fitting together the bones he acquired from Newburgh, fashioning the missing pieces out of wood and papier-mâché. He presented the skeleton to the public on Christmas Eve, 1801. To publicize the exhibition, Peale had his black servant, Moses Williams, don an Indian headdress and ride through the streets of Philadelphia on a white horse. The reconstructed beast stood eleven feet high at the shoulder and more than seventeen feet long from tusks to tail, a somewhat exaggerated size. Visitors were charged fifty cents—quite a considerable sum at the time—for a viewing. The beast, an American mastodon, at this point still lacked an agreed-upon name and was variously referred to as an incognitum, an Ohio animal, and, most confusing of all, a mammoth. It became America’s first blockbuster exhibit and set off a wave of “mammoth fever.” The town of Cheshire, Massachusetts, produced a 1,230-pound “mammoth cheese”; a Philadelphia baker produced a “mammoth bread”; and the newspapers reported on a “mammoth parsnip,” a “mammoth peach tree,” and a mammoth eater, who “swallowed 42 eggs in ten minutes.” Peale also managed to piece together a second mastodon, out of additional bones found in Newburgh and a nearby town in the Hudson Valley. After a celebratory dinner held underneath the animal’s capacious rib cage, he dispatched this second skeleton to Europe with two of his sons, Rembrandt and Rubens. The skeleton was exhibited for several months in London, during which time the younger Peales decided that the animal’s tusks must have pointed downward, like a walrus’s. Their plan was to take the skeleton on to Paris and sell it to Cuvier. But while they were in London, war broke out between Britain and France, making travel between the two countries impossible.

  Cuvier finally gave the mastodonte its name in a paper published in Paris in 1806. The peculiar designation comes from the Greek, meaning “breast tooth”; the cusps on the animal’s molars apparently reminded him of nipples.

  Despite the ongoing hostilities between the British and the French, Cuvier managed to obtain detailed drawings of the skeleton that Peale’s sons had taken to London, and these gave him a much better picture of the animal’s anatomy. He realized that the mastodon was far more distant from modern elephants than the mammoth was, and assigned it to a new genus. (Today mastodons are given not only their own genus but their own family.) In addition to the American mastodon, Cuvier identified four other mastodon species, all “equally strange” to the earth today. Peale didn’t learn of Cuvier’s new name until 1809, and when he did he immediately seized on it. He wrote to Jefferson proposing a “christening” for the mastodon skeleton in his Philadelphia museum. Jefferson was lukewarm about the name Cuvier had come up with—it “may be as good as any other,” he replied—and didn’t deign to respond to the idea of a christening.

  In 1812 Cuvier published a four-volume compendium of his work on fossil animals—Recherches sur les Ossemens Fossiles de Quadrupèdes. Before he began his “researches,” there had been zero vertebrates classified as extinct. Thanks for the most part to his own efforts, there were now at least forty-nine.

  As Cuvier’s list grew, so did his renown. Few naturalists dared to announce their findings in public until he had vetted them. “Is not Cuvier the greatest poet of our century?” Balzac asked. “Our immortal naturalist has reconstructed worlds from a whitened bone; rebuilt, like Cadmus, cities from a tooth.” Cuvier was honored by Napoleon and, once the Napoleonic Wars finally ended, was invited to Britain, where he was presented at court.

  The English were eager converts to Cuvier’s project. In the early years of the nineteenth century, fossil collecting became so popular among the upper classes that a whole new vocation sprang up. A “fossilist” was someone who made a living hunting up specimens for rich patrons. The year Cuvier published his Recherches, one such fossilist, a young woman named Mary Anning, discovered a particularly outlandish specimen. The creature’s skull, found in the limestone cliffs of Dorset, was nearly four feet long, with a jaw shaped like a pair of needle-nose pliers. Its eye sockets, peculiarly large, were covered with bony plates.

  The fossil ended up in London at the Egyptian Hall, a privately owned museum not unlike Peale’s. It was put on exhibit as a fish and then as a relative of a platypus before being recognized as a new kind of reptile—an ichthyosaur, or “fish-lizard.” A few years later, other specimens collected by Anning yielded pieces of another, even wilder creature, dubbed a plesiosaur, or “almost-lizard.” Oxford’s geology expert, the Reverend William Buckland, described the plesiosaur as having a lizardlike head joined to a neck “resembling the body of a Serpent,” the “ribs of a Chameleon, and the paddles of a Whale.” Apprised of the find, Cuvier found the account of the plesiosaur so outrageous that he questioned whether the specimen had been doctored. When Anning uncovered another, nearly complete plesiosaur fossil, Cuvier had to acknowledge that he’d been wrong. “One shouldn’t anticipate anything more monstrous to emerge,” he wrote to one of his British correspondents. During Cuvier’s trip to England, he visited Oxford, where Buckland showed him yet another astonishing fossil—an enormous jaw with one curved tooth sticking up out of it like a scimitar. Cuvier recognized this animal, too, as some sort of lizard. A couple of decades later, the jaw was identified as belonging to a dinosaur.

  The study of stratigraphy was in its infancy at this point, but it was already understood that different layers of rocks had been formed during different periods. The plesiosaur, the ichthyosaur, and the as yet unnamed dinosaur had all been found in limestone deposits that were attributed to what was then called the Secondary and is now known as the Mesozoic era. So, too, had the ptero-dactyle and the Maastricht animal. This pattern led Cuvier to another extraordinary insight about the history of life: it had a direction. Lost species whose remains could be found near the surface of the earth, like mastodons and cave bears, belonged to orders of creatures that were still alive. Digging back further, one found creatures, like the animals from Montmartre, that had no obvious modern counterparts. If one kept digging, mammals disappeared altogether from the fossil record. Eventually one reached not just a world previous to ours but a world previous to that, dominated by giant reptiles.

  Cuvier’s ideas about this history of life—that it was long, mutable, and full of fantastic creatures that no longer existed—would seem to have made him a natural advocate for evolution. But he opposed the concept of evolution, or transformisme, as it was known in Paris at the time, and he tried—generally, it seems, successfully—to humiliate any colleagues who advanced the theory. Curiously, it was the same skills that led him to discover extinction that made evolution appear to him preposterous, an affair as unlikely as alchemy.

  As Cuvier liked to point out, he put his faith in anatomy; this was what had allowed him to distinguish the bones of a mammoth from those of an elephant and to recognize as a giant salamander what others took to be a man. At the heart of his understanding of anatomy was a notion that he termed “correlation of parts.” By this he meant that the components of an animal all fit together and are optimally designed for its particular way of life; thus, a carnivore will have an intestinal system suited to digesting flesh. Its jaws will be “constructed for devouring prey; the claws, for seizing and tearing it; the teeth, for cutting and dividing its flesh; the entire system of its locomotive organs, for pursuing and catching it; its sense organs for detecting it from afar.”

  Conversely, an animal with hooves must be an herbivore, since it has “no means of seizing prey.” It will have “teeth with a flat crown, to grind seeds and grasses,” and a jaw capable of lateral motion. Were any one of these parts to be altered, the functional integrity of the whole would be destroyed. An animal that was born with, say, teeth or sense organs that were somehow different from its parents’ would not be able to survive, let alone give rise to an entirely new kind of cre
ature.

  In Cuvier’s day, the most prominent proponent of transformisme was his senior colleague at the National Museum of Natural History, Jean-Baptiste Lamarck. According to Lamarck, there was a force—the “power of life”—that pushed organisms to become increasingly complex. At the same time, animals and also plants often had to cope with changes in their environment. They did so by adjusting their habits; these new habits, in turn, produced physical modifications that were then passed down to their offspring. Birds that sought prey in lakes spread out their toes when they hit the water, and eventually developed webbed feet and became ducks. Moles, having moved underground, stopped using their sight, and so over generations their eyes became small and weak. Lamarck adamantly opposed Cuvier’s idea of extinction; there was no process he could imagine that was capable of wiping an organism out entirely. (Interestingly, the only exception he entertained was humanity, which, Lamarck allowed, might be able to exterminate certain large and slow-to-reproduce animals.) What Cuvier interpreted as espèces perdues Lamarck claimed were simply those that had been most completely transformed.

  The notion that animals could change their body types when convenient Cuvier found absurd. He lampooned the idea that “ducks by dint of diving became pikes; pikes by dint of happening upon dry land changed into ducks; hens searching for their food at the water’s edge, and striving not to get their thighs wet, succeeded so well in elongating their legs that they became herons or storks.” He discovered what was, to his mind at least, definitive proof against transformisme in a collection of mummies.

  When Napoleon invaded Egypt, the French, as usual, seized whatever interested them. Among the crates of loot shipped back to Paris was an embalmed cat. Cuvier examined the mummy, looking for signs of transformation. He found none. The ancient Egyptian cat was, anatomically speaking, indistinguishable from a Parisian alley cat. This proved that species were fixed. Lamarck objected that the few thousand years that had elapsed since the Egyptian cat was embalmed represented “an infinitely small duration” relative to the vastness of time.