In January 1613, workers at an estate in the Dauphiné, in southeastern France, unearthed a number of large bones. They included two mandibles with some teeth, a couple of vertebrae, what seemed to be a sternum, a shoulder blade, the heel and instep of a foot, the top of a humerus, and (the prize) a very long tibia. While the skull crumbled to dust as soon as it was exposed to air, a large jawbone with intact teeth remained.

A surgeon summoned to the scene asserted that the bones were human in origin. If this was true, they would have belonged to a very large human, some 8 meters (25 feet) tall; the leg bone alone was six feet (nearly two meters) long. Moreover, legend had it that a battle had been fought on this site in 150 BC between the Roman consul Marius and a giant barbarian king named Theutobochus. A recent edition of the History of the Roman historian Florus had described this battle, and noted the unusual size of the king. It took only a small leap of imagination to see Theutobochus in these bones.
Several people promoted this identification, including the estate’s owner, the Marquis de Langon, the surgeon who identified them as human, Pierre Mazuyer, and even King Louis XIII, aged 11. With the permission of the Marquis, Mazuyer organized an exhibit of some of the bones in Paris, which then traveled to the provinces.
However, not everyone was equally convinced that the bones were human. In reply to a pamphlet by Paris surgeon Nicolas Habicot, who declared that the bones were indeed those of Theutobochus, the eminent physician and anatomist Jean Riolan the younger issued a scathing rebuttal. The bones were not human, he declared, but might have belonged to an elephant or a whale. Most likely, God had simply formed them in the earth to resemble bones.
This latter claim had been a common explanation for fossil bones; the Swiss naturalist Conrad Gessner had stated such in his 1565 De omni rerum fossilium. Let me focus instead on Riolan’s first claim, that the bones resembled those of an elephant. This became a standard identification for such bones for the next entry and a half. Did these bones actually look like elephant bones? How much did Riolan and his contemporaries know about elephants?
The bones do not survive, except for a plaster cast of a tooth in the paleontology storage of the Paris Museum of Natural History. This cast led Museum paleontologist Léonard Ginsburg in 1984 to identify “Theutobochus” as a deinotherium, a Miocene ancestor of the elephant that pre-dated the more familiar mammoths and mastodons by several million years. Numerous deinotherium jawbones survive, with intact teeth, such as this one.

These teeth look more human than elephantine. In the absence of the deinotherium’s distinctive skull,

and in the presence of strong beliefs in the existence of exceptionally large giants in the past, it was not illogical to conclude, as Mazuyer and Habicot did, that the fossil jaw they saw belonged to a giant human. Neither they nor Riolan had ever seen a real elephant, and most contemporary descriptions and illustrations of elephants

show little acquaintance with the animal. These descriptions and images often exaggerated their size and other characteristics.
In the millions of years between the deinotherium and the modern elephant, teeth evolved from the bicuspid shape of the former to the flat grinding surface of the latter. Modern elephants are also smaller than their prehistoric ancestors. The contrast between the skeleton of Louis XIV’s elephant on the ground floor of the Paris Museum of Natural History and the huge leg bones

and skulls of deinotheriums, mammoths, and mastodons on the floor above is striking. In 1768, the Scots physician William Hunter compared the jawbones of an elephant and what he called the “American incognitum”

to prove that the latter was not an elephant but a member of an extinct species related to the “mammouths” of Siberia.
Most modern accounts of the bones of Theutobochus consider Mazuyer and Habicot as fraudsters who knew perfectly well that the bones were not human. Ginsburg, exceptionally, argued that they were sincere. What if we took them at their word? In 1613, giants continued to be possible, and the six-foot-long leg bone and human-like jaw of Theutobochus only confirmed to them that wondrous beings had indeed lived, and had left evidence of their existence.