The Bone She Was Told Wasn’t There

Lydia Mercer, the Dry Knife Expedition, and the Fossil That Embarrassed a Generation of Experts In the summer of 1914, a paleontologist whom many of her colleagues regarded as stubborn, impractical, and—most unforgivably—wrong led a poorly funded expedition into a stretch of badlands that senior scientists had already dismissed as worthless. Six weeks later, Lydia Mercer was kneeling beside a fossil that would force them to reconsider both the ancient landscape and the woman they had spent years refusing to take seriously. On the morning of 17 August 1914, Lydia Mercer was lying flat on her stomach in a shallow trench beneath a sandstone ledge, brushing dust from what she first thought was another fragment of petrified wood. The temperature had passed 100 degrees by ten o’clock. Two canvas water bags hung in the shade of a supply wagon fifty yards away. One had split during the night. The expedition cook had been ill for three days. A mule had gone lame. Their photographic plates were running low, and there was enough money left in the expedition account to purchase either another week’s provisions or rail freight for the specimens already collected. Mercer kept brushing. The brown curve in front of her was not wood. She called for a knife. Then a smaller brush. Then she asked everyone to stop walking. Within twenty minutes, the exposed surface had widened into a dense ridge of fossilized bone. By noon, Mercer could see the edge of an opening in the skull. By late afternoon, a second opening appeared farther back, followed by the unmistakable sweep of a broad frill buried beneath nearly four feet of compacted sediment. One of the men working with her reportedly stared at the exposed bone for several seconds before saying: “Good God, Mercer. You actually found the damned thing.” The fossil was unlike anything the expedition had expected to uncover. That was because almost nobody except Lydia Mercer had expected anything to be there at all. An Education in Being Overlooked Lydia Anne Mercer was born in 1878 in a railway town in western Pennsylvania, the second daughter of a schoolmaster and an amateur mineral collector. According to family accounts, she began filling matchboxes with stones before she could properly write their names. At thirteen, she was cataloguing fossils collected from local coal seams. At sixteen, she announced that she intended to become a geologist. Her father encouraged her. Most other people did not. Mercer entered the Harrington College for Women in 1896, where she studied geology, comparative anatomy, and zoology. She was an exceptional student, but the scientific world available to her was considerably smaller than the one available to men of similar ability. Lydia Anne Mercer during her graduate years, c. 1904. Women could attend lectures in some institutions but not join the societies that sponsored them. They could prepare specimens but were rarely placed in charge of collections. They could illustrate monographs, catalogue bones, translate European papers, and perform much of the patient work on which academic reputations were built. They were far less often permitted to build those reputations themselves. Mercer completed her doctoral research on the vertebrate fossils of the Redwater Formation in 1905. Her first substantial paper appeared under the name L. A. Mercer . This was not an accident. Dr. Lydia Anne Mercer at work in the vertebrate preparation laboratory, c. 1908. Years later, she told a former student that manuscripts submitted as “Lydia Mercer” tended to receive long letters explaining why her conclusions were “premature,” while manuscripts submitted as “L. A. Mercer” were more often returned with requests for minor corrections. After graduation, Mercer joined the American Institute of Vertebrate Geology as an assistant preparator. Her work included removing stone from fossil skeletons collected by male field expeditions, reconstructing damaged bones, maintaining catalogues, and preparing anatomical drawings. She was paid less than the junior male assistants whose mistakes she routinely corrected. During her first six years at the institute, Mercer contributed directly to nine published papers. Her name appeared on two. The Problem with the Dry Knife Basin Mercer’s great argument began with a box of teeth. Fossil teeth and fragments collected in the Dry Knife Basin by surveyor Thomas Bell, 1909. In the winter of 1909, a ranch surveyor named Thomas Bell arrived at the institute carrying several small fossil fragments he had collected in a remote badlands district known locally as the Dry Knife Basin . The specimens were unimpressive. A vertebral fragment. Two worn teeth. A piece of what appeared to be a limb bone. The institute’s senior paleontologists identified them as transported material—fossils eroded from older rocks elsewhere and redeposited in younger sediments. Mercer disagreed. The teeth bothered her. Their preservation matched the surrounding matrix too closely. More importantly, the rock adhering to the roots contained a distinctive mixture of pale volcanic ash and red clay that Mercer recognized from geological survey samples taken directly from the basin. She began studying old survey reports. Then railway-cut records. Then mineral assessments. Slowly, a possibility emerged. The established geological map of the Dry Knife region might be wrong. Mercer believed that a narrow band of fossil-bearing Cretaceous sediment ran beneath the western escarpment of the basin. If she was correct, the formation could contain the remains of large terrestrial vertebrates in an area where the institute’s authorities insisted such animals had never lived. Her proposed explanation was geological rather than spectacular. An ancient river system, she argued, had once flowed through the basin and deposited carcasses along a floodplain. Subsequent erosion had hidden most of the fossil-bearing layer beneath harder sandstone. To Mercer, the evidence was compelling enough to justify a survey. To several of her colleagues, it was amusing. At a departmental dinner in 1911, one senior scientist reportedly described Mercer’s proposed fossil bed as “Miss Mercer’s invisible menagerie.” Another suggested that if she wished to hunt imaginary animals she might “find better sport in mythology.” The joke followed her for years. A Grant for $300 In January 1912, Mercer submitted her first formal expedition proposal. She requested $1,850. The budget was modest even by contemporary standards. It covered rail transport, two wagons, draft animals, provisions, field tools, photographic supplies, and wages for a small crew. The scientific committee declined. Mercer revised the proposal. She reduced the planned expedition from twelve weeks to eight. Declined. She removed one field assistant. Declined. She offered to work without salary. The committee awarded her $300 for a preliminary survey, provided she travelled with a male field supervisor. The institute’s 1912 funding decision. Mercer had originally requested $1,850. The supervisor assigned to her had never visited the Dry Knife Basin. Mercer had spent three years studying it. The preliminary expedition nevertheless produced something important: a fragmentary horn core, several ribs, a series of vertebrae, and the partial jaw of a large herbivorous dinosaur. Mercer returned convinced that a major skeleton remained in the basin. Her supervisors returned convinced that she had been lucky. The institute declined to fund a second expedition. Catherine Ashcombe At approximately this point in the surviving private record, another name begins to appear. Catherine Ashcombe was eleven years older than Mercer and belonged to a family whose fortune came from shipping, steel, and railway investments. She was a widow. Her husband had died after only six years of marriage, leaving her financially independent and socially conspicuous. Catherine Ashcombe, c. 1912. The Philadelphia philanthropist became Mercer’s most important private supporter. Ashcombe collected books, botanical illustrations, antiquities, and scientific instruments. She attended public lectures at museums and universities and developed a particular interest in geology. She first heard Lydia Mercer speak in Philadelphia in February 1912. Mercer’s lecture was titled River Deposits and Vertebrate Distribution in the Western Cretaceous . It was not designed to be entertaining. Ashcombe attended anyway. Several weeks later, she invited Mercer to dinner. Their relationship developed slowly. At first, Ashcombe appears simply as a supporter. She purchased geological books for Mercer, introduced her to potential donors, and arranged access to privately held survey records. Then the tone of their correspondence changed. “My dear Dr. Mercer” became “Dear Lydia.” Then simply “L.” Lydia Mercer and Catherine Ashcombe, c. 1913. Publicly, Ashcombe was described as Mercer’s patron and friend. Mercer, usually restrained even in personal letters, began signing hers “Yours, always.” The exact nature of their relationship was never publicly acknowledged during either woman’s lifetime, but the surviving correspondence leaves little ambiguity. They were lovers. For Mercer, the relationship carried considerable risk. A woman already struggling for professional legitimacy could ill afford rumors about an intimate friendship with a wealthy widow. Ashcombe had more social protection, but she too understood the danger. When they travelled together, they often booked separate rooms. In public, Ashcombe was described as Mercer’s “patron” or “friend of scientific work.” In private, she became something more consequential. She became the person who believed Mercer when almost nobody else did. “Then We Shall Pay for It Ourselves” By 1913, Mercer had assembled enough evidence to propose a full excavation of the Dry Knife Basin. The institute again refused. A committee member argued that the previous finds were too fragmentary to justify the cost. Another wrote that Dr. Mercer possessed “a tendency to interpret isolated evidence with excessive enthusiasm.” Mercer was furious. Ashcombe was practical. According to a letter preserved among Mercer’s papers, Ashcombe asked how much the expedition would actually cost. Mercer estimated $4,000 if they operated economically. Ashcombe replied: “Then we shall pay for it ourselves, and afterward they may explain why it was impossible.” Ashcombe eventually provided approximately seventy percent of the expedition budget. The remainder came from small donations, Mercer’s personal savings, and a reluctant contribution from the institute, which agreed to lend equipment on the condition that any significant specimens would become part of its collection. Even then, Mercer was not officially named expedition director. The institute designated her Scientific Field Associate . The title of director went to Professor Edwin Harcourt, a respected geologist who had agreed to accompany the party. Harcourt was sixty-two years old. He lasted nineteen days. Into the Badlands The Dry Knife Expedition left by rail in June 1914. The party included Mercer, Harcourt, two graduate assistants, a photographer, a fossil preparator, three hired laborers, a cook, and a local guide. Their equipment filled two freight wagons. They carried tents, plaster, burlap, chisels, picks, shovels, brushes, canvas water bags, collecting trays, notebooks, specimen tags, wooden crates, photographic plates, surveying instruments, and nearly two hundred pounds of flour. The Dry Knife expedition camp, summer 1914. Water, supplies and photographic equipment had to be hauled considerable distances into the basin. The basin proved worse than Mercer had predicted. Daytime heat cracked wooden tool handles. Night temperatures fell sharply. Fine dust entered everything: camera mechanisms, bedding, food tins, eyes, lungs. Water had to be hauled from a spring nearly six miles from camp. A flash flood destroyed part of their first excavation trench. Scorpions found their way into boots. One horse broke through a crust of hardened earth and injured its leg. Then Harcourt developed a severe gastrointestinal illness. He returned east on 12 July. His departure created an awkward administrative problem. According to the institute, the expedition was now without its director. According to everyone remaining at the camp, Lydia Mercer was obviously in charge. She reorganized the work schedule, moved the main camp closer to the western escarpment, and ordered the crew to abandon two unproductive trenches. The decision was unpopular. They had spent almost three weeks opening those sites. Mercer insisted the geology was wrong. She had noticed a thin band of gray-green clay exposed beneath the sandstone several hundred yards farther north. It matched sediment attached to the original teeth that had first interested her five years earlier. The camp moved. Three days later, they found bone. The First Sign The initial discovery was disappointingly small. A section of rib. Then another. Several feet away, a graduate assistant uncovered a vertebra. Mercer ordered the team to stop digging vertically. Instead, they began removing sediment in broad horizontal layers. The work was painfully slow. Fossilized bone is not simply lifted from the ground. It must be exposed gradually, stabilized, mapped, photographed, and often protected with plaster before it can be moved. The ribs led toward a mass of harder stone. For nearly a week, the team could not determine whether the skeleton continued into it. Then came the morning of 17 August. Mercer’s brush touched the first part of the skull. By evening, enough had been exposed to establish that they were dealing with an unusually large ceratopsian—a horned dinosaur related to forms already known from western North America. But several features appeared wrong. The skull was unusually deep. The nasal structure was broad and heavily fused. The brow horns projected at an unexpected angle. Most strikingly, the rear of the skull possessed a short, thickened frill with an arrangement of openings and marginal bones that none of the scientists present could confidently match to a known specimen. Mercer did not announce a new species. She was too careful for that. She wrote in her notebook: “Large ceratopsian. Skull substantially complete. Morphology unfamiliar. Must not speculate until preparation.” Below that, in smaller handwriting, she added: “I think we have it.” The Photograph The famous expedition photograph was taken the following morning. Mercer kneels beside the exposed skeleton. Five men stand around her. Crates and tools lie at the edge of the trench. Behind them rise the eroded cliffs of the Dry Knife Basin. Mercer is looking toward the camera. The others are looking at the fossil. It is an extraordinary image partly because nothing in it appears extraordinary. Lydia Mercer with members of the Dry Knife Expedition beside the partially exposed specimen, August 18, 1914. There are no raised arms. No champagne. No theatrical celebration. Only exhausted people standing around a collection of ancient bones that none of them yet fully understands. But the photograph captures a moment of reversal. For years, Mercer had been asked to prove that fossils existed in the Dry Knife Basin. Now the fossil was there. The burden of explanation belonged to everyone else. Getting the Fossil Home Finding the skeleton was only the beginning. The specimen was too fragile to remove quickly. The skull alone weighed several hundred pounds with its surrounding matrix. The team dug around the bones, coated exposed surfaces with preservative, wrapped sections in wet plaster and burlap, and constructed wooden reinforcement frames. Money was disappearing. Ashcombe sent additional funds by telegraph. A supply wagon broke an axle. Heavy rain turned the basin floor into mud. One plaster jacket cracked while being lifted and had to be rebuilt. The largest block required a makeshift timber sled and six horses to move less than half a mile. Members of the expedition hauling the plaster-jacketed skull block from the excavation, August 1914. Mercer remained at the site until the final crate departed. She had lost nearly fifteen pounds during the expedition. In photographs taken after her return, her face appears noticeably thinner. Catherine Ashcombe met her at the railway station. There is no photograph of that reunion. Perhaps appropriately, the most important relationship in Mercer’s life remains largely outside the public record. The Experts Arrive The fossil reached the institute in October 1914. Mercer working on the partially prepared Dry Knife skull after its arrival at the institute, late 1914. Almost immediately, the argument changed. No serious observer could now claim that Mercer had discovered nothing important. Instead, critics began arguing that the specimen was not as important as Mercer believed. Professor Nathaniel Voss, one of the men who had opposed funding the expedition, suggested that the unusual skull proportions resulted from geological distortion. Another specialist proposed that it was merely a juvenile example of a known genus. A third argued that the specimen had probably washed into the Dry Knife sediments from an older formation. Mercer systematically dismantled each explanation. The skull showed little crushing. The sutures indicated a mature animal. The surrounding sediment matched the local formation. Several associated bones had been recovered in anatomical position. Most importantly, preparation revealed features that could not easily be dismissed as deformation. The animal possessed a combination of traits not known in any previously described ceratopsian. By early 1916, even some of Mercer’s strongest critics privately accepted that the specimen represented a distinct form. Publicly, they were slower. Who Gets Credit? The first major institutional report on the discovery appeared in 1915. Its title referred to the Harcourt Expedition to the Dry Knife Basin . Harcourt had left the expedition a month before the fossil was discovered. Mercer protested. The institute declined to change the title, explaining that Harcourt had been the expedition’s officially appointed director. Newspaper reports were worse. One described Mercer as “the lady assistant who noticed the first bone.” Another credited “Professor Harcourt’s party” with the discovery. A third devoted more space to Catherine Ashcombe’s wealth than to Mercer’s geology. The scientific establishment had discovered a useful compromise. It could accept the fossil without accepting the woman responsible for finding it. Mercer refused to cooperate. She prepared the specimen herself. She rechecked the field measurements. She compared the skull with every major ceratopsian specimen available to her. And she wrote the monograph. When one senior colleague suggested that a male co-author might make publication “easier,” Mercer reportedly answered: “Easier for whom?” The paper appeared under her name alone. Merceroceratops insolitus Title page of Mercer’s 1917 monograph formally describing the Dry Knife specimen. In 1917, Lydia Mercer formally described the Dry Knife animal as a new genus and species: Merceroceratops insolitus . The name roughly conveyed the idea of an unusual horned face, though colleagues jokingly observed that Mercer had finally succeeded in attaching her own name to something the institute could not remove. The description was conservative. Mercer did not claim that the animal overturned dinosaur evolution. She did not announce a missing link. She did something more scientifically important. She demonstrated that large ceratopsians occupied a broader range of environments than previously assumed and that the Dry Knife sediments belonged to a fossil-bearing interval older than the institute’s mapping had indicated. Her supposedly impossible fossil had exposed an error not merely in taxonomy but in regional geology. Later expeditions found additional dinosaur material in the basin. Fragments of turtles, crocodilian remains, small theropod teeth, plant impressions, and several partial herbivore skeletons followed. The “empty” formation became a productive research area. The Attempts to Shrink the Discovery Recognition did not arrive gracefully. For years, some senior researchers referred to Merceroceratops as “Mercer’s variant,” implying that it would eventually be absorbed into another genus. Scientific press coverage reflecting continued skepticism about Mercer’s proposed new genus, 1916. Conference speakers discussed the Dry Knife fauna without mentioning the person who had predicted it. One textbook reproduced Mercer’s geological interpretation while citing a later paper written by two male researchers. Even Catherine Ashcombe’s financial contribution was treated dismissively. Private funding from industrialists had supported paleontology for decades. Yet when the donor was a woman—and particularly a woman closely associated with another woman—commentators sometimes described the expedition as a wealthy amateur’s indulgence. Ashcombe appears to have been amused rather than offended. In one letter to Mercer, she wrote: “Apparently when Mr. Carroway pays for a museum wing it is philanthropy, but when I pay for six mules and three tons of plaster it is eccentricity.” Mercer kept the letter for the rest of her life. Beyond the Fossil The Dry Knife discovery changed Mercer’s career, although less dramatically than later accounts sometimes suggest. She did not suddenly become head of the institute. She was not immediately given a professorship. She continued to fight for laboratory space, field budgets, and formal authority. But she could no longer be dismissed as an assistant who had wandered beyond her expertise. In 1920, she became Curator of Western Vertebrate Paleontology. In 1924, she led another expedition under her own name. She trained several younger researchers, including women whom she deliberately sent into the field rather than confining to preparation rooms. Her lectures became popular with students because she insisted that scientific certainty should always remain vulnerable to evidence. “The map,” she once told a class, “is only our present opinion of the ground.” Mercer and Catherine Ashcombe remained close for more than twenty years. They never lived together openly. Ashcombe maintained a townhouse in Philadelphia and a country property outside the city. Mercer kept rooms near the institute. But letters indicate long visits, shared holidays, and a domestic intimacy carefully hidden behind the respectable language of friendship. When Ashcombe died in 1936, she left Mercer her scientific library and a substantial portion of her estate. The public obituary described Mercer as “a lifelong friend.” Mercer never corrected it. The Fossil in the Museum Today—within the history presented here—the reconstructed skull of Merceroceratops insolitus would occupy a central gallery in the institution that once refused to finance its discovery. The mounted skeleton of Merceroceratops insolitus in the institute’s main vertebrate gallery, c. 1924. The original field photograph would hang nearby. Visitors might first notice the enormous skull. Then the ribs. Then the group of scientists surrounding the excavation. Eventually, they would notice the woman kneeling at the center. That sequence is strangely appropriate. For much of Lydia Mercer’s career, people saw the science before they saw the scientist. Her colleagues doubted her conclusions because they believed the accepted geological maps. Funding committees doubted her judgment because successful expeditions were supposed to be led by men. Critics doubted the fossil because accepting it required admitting that she had understood the basin better than they had. Mercer endured all three doubts. She did not defeat them through rhetoric. She dug through them. Layer by layer. Until the evidence was visible. The Last Entry Among Mercer’s field notebooks, the final page of the 1914 expedition contains an unusually personal entry. Most of her notes are measurements. Temperatures. Coordinates. Bone numbers. Sediment descriptions. On the last page, written while the fossil crates were being prepared for transport, she allowed herself four sentences. August 29. Skull secure. Rain expected. Two wagons leave tomorrow. C. was right to insist we come. Then, below the scientific notes, she added one final line: Final entry in Mercer’s Dry Knife field notebook, August 29, 1914. There are few pleasures greater than finding what sensible people have assured you cannot exist. More than the naming of a species or the correction of a geological map, that sentence may be the best summary of Lydia Mercer’s career. The Dry Knife fossil mattered because it altered what scientists believed about an ancient world. Lydia Mercer mattered because she refused to allow the modern one to decide in advance what she was permitted to discover. Editor’s note: Lydia Mercer, Catherine Ashcombe, the Dry Knife Basin, the institutions, correspondence, expedition, and fossil described in this feature are fictional. The story is written in the style of a historical scientific-magazine article and draws on the real professional barriers faced by women working in geology and paleontology during the late 19th and early 20th centuries.