Before Science: How Medieval and Early Modern Societies Explained Giant Fossils

Mammals emerged over 200 million years ago, lingering alongside dinosaurs as small, mouse-like creatures. Following the asteroid impact 66 million years ago, they underwent a dramatic diversification, initiating the Age of Mammals. However, the journey toward scientifically understanding this evolutionary branch was fraught with myth and dogma. In an excerpt from his upcoming book, The Story of Mammals in 25 Discoveries, author Donald R. Prothero examines a historical period when early philosophers and naturalists interpreted fossils through the lens of mythology, often viewing the concept of extinction as heretical.

Global folklore is replete with legends of colossal human races that inhabited the Earth in ancient times, sometimes clashing with deities or perishing in great floods. These narratives were frequently bolstered by archaeological discoveries of enormous bones found throughout the Mediterranean and Europe, far exceeding the size of any known human skeleton. The Greek philosopher Empedocles, living between 492 and 432 BCE, documented such giant remains in Sicily, attributing them to a lost race of giants. Similarly, the Roman historian Pliny the Elder (23-79 CE) noted fossilized ivory found underground, while Suetonius (69-122 CE) recorded that Emperor Augustus possessed a collection of large bones recovered from Capri, near Pompeii.

误解 often arose from the morphology of these fossils. Elephant skulls, distinguished by their large frontal orbits designed for trunks, were frequently misidentified as the skulls of one-eyed cyclopes. During the Middle Ages, massive bones were commonly ascribed to giants or monsters referenced in Genesis, believed to have been submerged during Noah’s flood. Siberian giant tusks were interpreted as the horns of mythical unicorns or the teeth of dragons, while mammoth vertebrae and teeth in certain regions were venerated as relics of saints. Strikingly, the correct identification of these remains as extinct elephants was almost entirely overlooked.

By the early 17th century, interpretations remained eclectic. Giant bones excavated from a sand pit near Langon in southeastern France were toured across the country as evidence of the Teutons, Germanic tribes defeated by the Romans in 101 BCE. This prevailing view was challenged in 1613 by the anatomist Riolan, who proposed that the bones belonged to an elephant. His assertion ignited a fierce debate between physicians and barber-surgeons, who insisted they were human remains. Alternative explanations included claims of hoaxes or the influence of vis plastica, or “plastic forces,” thought to permeate the Earth. Theological objections also arose, with critics accusing anatomists of contradicting biblical accounts of giants. Although the controversy subsided by 1618 without resolution, the tendency to attribute new fossil finds to gigantic humans persisted for two centuries.

Fossils discovered in the New World generated similar confusion and awe. Indigenous tribes often integrated these bones into their oral traditions, viewing them as remnants of giant monsters fought by their ancestors. When European colonists encountered them, interpretations varied: some saw proof of biblical giants, while others, like Reverend Cotton Mather of the Massachusetts Bay Colony in 1706, dismissed them as demonic temptations. Mather described them as the remains of “godless giants” drowned in the Flood and sent samples to the Royal Society in London for verification, noting that biblical scholars were calculating Adam’s height at over 123 feet. The Royal Society did not issue a definitive ruling, though skepticism regarding literal biblical interpretations was growing among its members.

Religious doctrine imposed a significant barrier to accepting extinction. The concept of Divine Providence suggested that an omnipotent and benevolent God would not permit any of His creations to vanish. The poet Alexander Pope articulated this in An Essay on Man (1734), writing, “who sees with equal eye, as God of all, a hero perish, or a sparrow fall.” The prevailing philosophical framework was the “great chain of being,” which posited a continuous hierarchy linking animals, humans, angels, and God. It was believed that breaking any link in this chain would collapse the entire structure. Pope further wrote, “From Nature’s chain whatever link you strike, Ten or ten thousandth, breaks the chain alike.”

By the late 18th century, empirical evidence increasingly suggested that many fossils had no modern counterparts. As explorers ventured into remote regions of South America, Africa, and the East Indies, they discovered numerous new species but failed to find the gigantic beasts implied by the fossil record. Fossils of animals such as hippos, found in Paris and London, were generally attributed to having been washed out of tropical zones during the Great Flood, preserving the idea that extinction was a blasphemous notion.

Evidence from North America eventually provided clearer answers. In 1739, Charles le Moyne, Baron de Longueil, discovered skeletal remains resembling three elephants while campaigning with French and Indian troops along the Ohio River against the Chickasaw. After the war concluded in 1740, he transported the bones to Paris, where they attracted the attention of French naturalists. Around the same time, Benjamin Franklin encountered fossils in Kentucky that puzzled him; while resembling elephants, their teeth differed from any known species. Between the 1740s and 1750s, settlers from Big Bone Lick, Kentucky, sent more specimens to Franklin and to England. These were later identified as American mastodons (Mammut americanum).

Franklin initially speculated that the teeth indicated a carnivorous diet, though he and others later revised this to herbivory. In 1769, British anatomist William Hunter took the carnivorous hypothesis seriously, proposing the animal was a “pseudelephant” or “American incognitum” (unknown). Hunter vividly described this creature as possessing the agility of a tiger and the ferocity of a panther, remarking, “if this animal was indeed carnivorous… we cannot but thank Heaven that its whole generation is probably extinct.” Despite this early insight, the scientific community remained resistant to the idea of extinction.

As fossils of the “incognitum” and Siberian mammoths—including preserved carcasses with hair and skin—continued to surface, Georges-Louis Leclerc, Comte de Buffon, began to shift perspectives. In his 1749 Theorie de la terre, Buffon suggested that while many supposed extinct animals might hide in unexplored regions, large mammals like mammoths and mastodons had likely perished. By 1778, he linked their disappearance to violent geological cataclysms in Earth’s early history, proposing a warmer climate when polar regions were tropical. This implied an Earth far older than the 6,000 years advocated by literalist scholars, estimating its age between 75,000 and 3,000,000 years. Although the Sorbonne theologians opposed these views, Buffon was protected by the king and avoided persecution, though his ideas remained controversial.

The definitive proof of extinction was ultimately established by Baron Georges Cuvier (1769-1832), widely regarded as one of history’s greatest scientists. Described as tall with a massive head and a commanding presence, Cuvier possessed an exceptionally large brain, weighing 1,830 grams—significantly above the average even by modern standards. He revolutionized natural history by moving it beyond mere cataloging. Through extensive dissection and analysis of anatomical similarities and differences, he founded the field of comparative anatomy. Receieving fossil specimens from across the globe, Cuvier correctly identified many extinct species, including the mastodon and the marine reptile now known as the mosasaur, earning him the title of founder of vertebrate paleontology. His “law of correlation of parts” demonstrated that anatomical features are functionally linked; for instance, carnivores possess sharp teeth and claws, while herbivores have flat grinding teeth and hooves. This principle allows scientists to reconstruct complete organisms from fragmentary remains. The narrative of how humanity came to understand mammals is further explored in Prothero’s The Story of Mammals in 25 Discoveries.