A few blocks from Duke’s East Campus, there is a small building whose past lives include a dentist office, a real estate office, and a daycare. Now it is a museum.
With over 35,000 specimens, the Duke Lemur Center Museum of Natural History holds the largest and most diverse collection of primate fossils in North America.
Glass cases in the front room are lined with ancient fossils and more recent specimens less than 10,000 years old. Take Lagonomico, a creature that lived some 12-15 million years ago and whose name means “pancake,” in reference to the smashed shape of its remains. Or the tiny skull of a modern-day cotton-top tamarin. Even the enormous egg of an elephant bird, a ten-foot-tall bird that lived in Madagascar until it went extinct sometime in the last 1000 years.
A back room holds fossil discoveries still encased in rock. Special tools and scanning technology will reveal the creatures inside, relics of a very different world that can still yield revelations millions of years after their deaths.
Matt Borths, Ph.D., curator of the Duke Lemur Center’s fossils, explained that while many fossil collections focus on a particular location, this one has a different theme: the story of primate evolution.
Lemurs, Borths said, are our most distant primate relatives. About 60 million years ago, soon after the extinction of the dinosaurs, the “lemur line and monkey-ape-human line split.” Studying both modern lemurs and their ancestors can give us a “glimpse of a distant past.”
Primates are a group of mammals that include humans and other apes, monkeys, lemurs, lorises, bushbabies, and tarsiers. Many primates today live in Africa and South America, but they did not originate on either continent. Primates are believed to have evolved further north and migrated into Africa about 50 million years ago. As the global climate grew cooler and dryer, equatorial Africa remained warm and wet enough for primates. Over time, apes, monkeys, and lemurs diverged from their shared primate ancestors, but not all of them stayed in Africa.
Africa is currently home to bushbabies and lorises, which are both lemur relatives, but most of lemur evolution and diversification took place in Madagascar, the island nation where all of the world’s 100 species of lemurs live today. “New World monkeys,” meanwhile, are found in South America. How did lemurs and monkeys get from Africa—which was at the time completely surrounded by water—to where they live today? Both groups are believed to have crossed open ocean on rafts of plant material.
Scientists have direct evidence of modern animals rafting across bodies of water, and they believe that ancient lemur and monkey ancestors reached new land masses that way, too. Mangrove systems, adapted to ever-changing coastal conditions, are particularly prone to forming rafts that break away during storms. Animals that are on the plants when that happens can end up far from home. Not all of them survive, but those that do can shape the history of life on earth.
“Given enough time and enough unfortunate primates,” Borths said, “eventually you get one of these rafts that goes across the Mozambique Channel” and reaches Madagascar. Madagascar has been isolated since the time of the dinosaurs, and most of its species are endemic, meaning they are found nowhere else on earth. When lemur ancestors reached the island, they diversified into dozens of species filling different ecological niches. A similar process led to the evolution of New World monkeys in South America.
The history of primate evolution is still a work in progress. The Duke Lemur Center Museum of Natural History seeks to fill in some of the gaps in our knowledge through research on both living lemurs and primate fossils. This museum, Borths said, “brings basically all of primate evolution together in one building.” Meanwhile, living lemurs at the Lemur Center can help researchers understand how primate diets relate to teeth morphology, for example.
Paleontology is the study of fossils, but what exactly is a fossil? The word “fossil,” Borths said, originally referred to anything found in the ground. Over time, it came to mean something organic that turns to stone. Some ancient organisms are not fully fossilized. They can still preserve bone tissue and even proteins, evidence that they have not yet transformed completely into stone. The current definition of a fossil, according to Borths, is “anything from a living organism that is older than 10,000 years old.” Specimens younger than that are called subfossils.
The Lemur Center does important research on fossils, but that is not the only component of its mission. Education Programs Manager Megan McGrath said that the Lemur Center weaves together research, conservation, and education in an “incredibly unique cocktail” that “all forms a feedback loop.” McGrath and Borths also co-host a Duke Lemur Center podcast.
Conservation is a crucial component of the study of lemurs. Lemurs are the most endangered mammals on the planet, and some are already gone.
Human and wildlife survival are interlinked in complex ways, and conservation solutions must account for the wellbeing of both. Subsistence agriculture and other direct human activities can decimate ecosystems, but extinctions are also caused by broader issues like climate change, which threatens species on a global scale. Humanity’s impact on Madagascar’s wildlife over the last several thousand years is a “really complicated puzzle to tease apart,” McGrath said.
Some of the museum’s specimens are truly ancient, but others are from modern animals or species that went extinct only recently. Giant elephant birds roamed Madagascar as recently as a thousand years ago. The sloth lemur may have survived until 400 years ago. Borths puts the timescale of recent extinctions into perspective. At a time when modern species like the white-tailed deer were already roaming North America, Madagascar was still home to creatures like sloth lemurs and ten-foot elephant birds.
A model of a sloth lemur hangs in the museum, but no one alive has ever seen one breathing. No one will ever see or hear one again. But a ghost of it may exist in Malagasy stories about the tretretre, a monster that was said to have long fingers and a short tail. The word tretretre is thought to be an onomatopoeia of the call of a sloth lemur, an animal whose own voice is gone forever.
Learn about these and other stories of our evolutionary cousins at the museum’s next open house on Saturday, November 23, from 1-4 PM.
Post by Sophie Cox, Class of 2025