fossils saved – Johanna Gabriela Ottilie “Tilly” Edinger used fossilized skulls to study how brains evolved—work that helped her escape Nazi Germany in 1939 and helped create paleoneurology. From an endocast found during doctoral research to a life saved by an American job at
In November 1938, the work ended not with an experiment failing, but with a door closing.
Johanna Gabriela Ottilie “Tilly” Edinger had spent more than 15 years researching and tending fossils at the Senckenberg Museum in Frankfurt. Then. in a moment that felt final. Nazi authorities would not let her come back to work—or even enter the building. Jews were being expelled from schools, stripped of citizenship, and banned from working in public institutions. The museum was private, and Edinger was technically a volunteer, not a paid employee. She still wasn’t safe. The pressure that had been building for years became direct refusal.
By the night of November 9. 1938—known later as Kristallnacht—Nazis burned down and vandalized synagogues and Jewish businesses across the country. Edinger later wrote that she walked through Frankfurt with broken glass crunching underfoot and saw no police, only grinning faces. People had been telling her for years to get out. Even so, she kept coming into the museum. After Kristallnacht, there could be no more pretense of normal life.
She also made a prediction in a letter: one way or another, fossils would save her.
It wasn’t just courage. It was the kind of hope built from an unusual scientific conviction.
Edinger’s field began with a simple problem: how much can you understand about a brain after that brain is gone?. Paleontologists could find skulls, but brains didn’t survive as brains. The answer. for Edinger. was to study endocasts—natural casts of the inside of a cranium formed when fossil skulls fill with mud that hardens. The shape could roughly match the missing brain.
During her doctoral work at the University of Frankfurt. her advisor told her to look at Nothosaurus. a marine reptile from the Triassic period. He suggested she study the “palate” of its mouth and then left her to complete the thesis. While working on that creature, Edinger encountered an endocast. She wrote up her findings describing the relative sizes of the brain areas she could see. and she investigated how well an endocast could match the original brain that had been there. She published this work in 1921, and the next year she received her diploma from the University of Frankfurt.
At 24, Edinger had a doctorate in science in the 1920s. What she did with it took a different route than the one imposed on her later by Nazi policy. Instead of stepping away from her early discovery, she turned it into a career.
She began unpaid labor at the university’s Geology/Paleontology Institute and the Senckenberg Museum—both located in the same building—and volunteered there. It wasn’t unusual in Frankfurt for wealthy people to do this, especially since the museum relied on these volunteers. Edinger, though, didn’t treat the arrangement as temporary. She wrote. researched. and published “furiously.” Within a few years. she established a new field called paleoneurology. and she laid it out in a book she wrote during her time at the Senckenberg. Die Fossilen Gehirne (fossil brains).
That book treated endocasts as more than an afterthought. Edinger showed how paleontologists could study the brains of extinct animals and, crucially, how to do it. Her work went far enough to make her name recognizable well beyond Germany. Years later, in exile, that reputation would matter.
Her science also carried a sense of pattern—evolution visible through skulls arranged from older to younger forms. One example she published on in 1933 involved Sirenia, the group that includes manatees and dugongs. Edinger arranged endo casts from most ancient to most recent and showed changes such as decreasing relative olfactory lobe size compared with overall brain size. In other words: as these animals became more aquatic, the capacity for smelling appeared to diminish.
By the time her field was established, the world around her was tightening.
In the 1930s, life progressively worsened for Jewish people. Edinger stayed in Germany after Hitler took power. She was there when Jews were stripped of citizenship in 1935, and she was there for Kristallnacht in 1938. Her sister had already left for Turkey in 1933. People urged Edinger to get out. She reportedly told a friend she wasn’t worried about ending up in a concentration camp.
In her writing, she carried Veronal, a brand name at the time for Barbital that was lethal at a certain dose. She didn’t have to use it—at least not in the way she feared.
The “save her” part of her prediction came through a chain of professional recognition that arrived just in time.
In the late 1930s, her international reputation had reached the United States. Alfred Romer—an American paleontologist—eventually got her a job at the Harvard Museum of Comparative Zoology. Edinger called him her “angel chef” and “angel boss. ” because he had never met her in person. yet was willing to offer her a position based on her book. The job wasn’t fully funded. and the arrangement gave her a title and a tiny stipend so it could be official.
England, too, was willing to take her for a year before her number came up for entry into the United States.
Edinger left Germany in May 1939. By that point, as a Jew, she was not allowed to enter museums and was not allowed to enter movie theaters or cafes. When she left the country, she was not allowed to take much with her—basically nothing.
She arrived in Cambridge with almost nothing, but she made it. In later recollections, the contrast was stark: she had lost “every penny,” losing most of what she had. One account described her apartment as very close to the museum. and not what she was used to—she had to cook for herself. Another detail that stood out was her unfamiliarity with housework.
In America, Edinger found not only a place to work but a rhythm she had not expected. Katie Hafner. host and co-executive producer of Lost Women of Science. described Edinger’s story in terms that stick: there were “no cats in America. ” only to find that American life felt like something Edinger could finally breathe.
Romer’s role was part of the atmosphere. He was known for picnics and parties, and for treating everyone like part of a family. In the United States, Edinger taught zoology at Wellesley College because the museum had almost no funding for her position. In the late 1950s, she explained in an interview with Radio Bremen that the girls there liked her. She found the explanation strange. because they didn’t say they wanted her back for her ability to teach or her work as a scientist—they said the girls liked her. Edinger reportedly reacted with a line that translates as: “Don’t you find that un-German and very American?”.
Her gratitude was also personal. Edinger had lived for years in Germany with unpaid volunteer labor. In America, she felt she had been given a position scraped together to save her. She also described a protective dynamic with Romer: she vented in a long journal entry about a horrible editor who was power-tripping. and when she had to meet the editor. Romer was in the room. Edinger felt protected—Romer looked out for her.
Her family story, meanwhile, carried the cost that could not be escaped.
After the war, Edinger came back to Frankfurt and described the city as ruined and empty. In German. she recounted that her brother was gassed; her favorite cousin and one of her fathers were shot; and an aunt—the favorite aunt at the age of 80—received notice to prepare for deportation and took her own life. Another aunt died in a concentration camp. The pain is in the specificity: names were lost, and the emptiness had a timetable.
Through it all, she kept writing.
In the United States, Edinger published a second, well-known tome—this time on horses. Her earlier joking remark that Americans would be able to study horse brain evolution because they seemed uninterested elsewhere became a challenge from George Gaylord Simpson. who was apparently told to her to “do this.” What she expected to be straightforward turned out harder than she anticipated. but she completed it. finding evolutionary changes in horse brains over time.
She also addressed how the brain could develop more capacity without always simply getting bigger. The explanation. as described in the podcast conversation. was anatomical: the cells are on the outside of the brain. while wiring is on the inside. A smooth, round brain has limited surface area for expanding processing without becoming much larger. The result is that brains become more folded and curvier as they evolve. increasing surface area for the cellular “outside” where more capacity can develop.
By then, Edinger’s hearing loss—something that had started in her teens—had progressed. Her final years were harder. She couldn’t hear what people were saying at conferences. felt left out of conversations. and sometimes had trouble falling asleep because she was too nervous to hear the morning alarm.
Still, she kept working. Even after her formal retirement in 1964, she had projects she was excited about. One of them—work her colleagues finished after her death—became an important reference work for the field.
But her end came suddenly in Cambridge in 1967. While out walking, Edinger was hit by a delivery truck. She died later in hospital. It was claimed that she might not have heard the truck coming, possibly because her hearing aid was turned off at the time. She was 69.
In the broader story, Edinger’s legacy is less about a single headline-making breakthrough than about foundations that allow other scientists to build.
She created a new sub-discipline of paleontology: paleoneurology. Much of her work was described as methodical—collecting fossils, organizing them by time, describing shapes, and tracing evolutionary patterns through endocasts.
That method still matters. Modern paleoneurology has new tools, but it keeps returning to the same premise Edinger made concrete: fossils can preserve clues about brains that are otherwise gone.
As paleoneurologists do today. some researchers study “digital endocasts.” Instead of making an endocast by pouring silicone or latex into a skull—which might damage it—scientists perform CT scanning of a skull. then build a three-dimensional model of the brain cavity. The field can use micro-CT scanners for smaller specimens. and for something very large like a triceratops skull. researchers may go to a hospital for scanning. The process becomes a careful way to read the shape of a missing organ.
A contemporary paleoneurologist, Ashley Morhardt—an associate professor of anatomy and neuroscience at Washington University in St. Louis—described being familiar with Edinger as more than a name. The book. the chain-smoking outside the museum. the early life shaped by a father who was a human neurologist—these were details she knew well. Morhardt said Edinger was known widely within vertebrate paleontology, a “superstar” in a niche.
That niche, once it exists, changes what later researchers can do. It also changes what students learn, and what the wider public forgets.
Edinger’s life has a hard lesson tied to its improbable pivot. In November 1938, she was banned from the building where she had worked for more than 15 years. The Nazis tightened their grip across schools, citizenship, and employment. Kristallnacht turned the streets into a warning. And in that moment. she leaned on a belief rooted in her science: that the evidence she had painstakingly studied—fossil brains made visible as casts—could open a door.
A job at the Harvard Museum of Comparative Zoology in 1939 did that. She escaped. She built a field. And even now. when researchers scan skulls and model brain cavities digitally. they’re still traveling along the same path Edinger laid down: trying to understand the brain by studying what time left behind.
Tilly Edinger paleoneurology fossil brains endocasts Nazi Germany Kristallnacht Alfred Romer Harvard Museum of Comparative Zoology horse brain evolution Alfred P. Sloan Foundation Anne Wojcicki Foundation