Mayor Brandon Johnson and Cook County Board President Toni Preckwinkle to attend unveiling of the Chicago Archaeopteryx.

Every bird you’ve ever seen— every pigeon at a bus stop, every penguin at the zoo— is a living, breathing dinosaur. Birds are the only group of dinosaurs that survived the mass extinction caused when an asteroid hit the Earth 66 million years ago. A fossil called Archaeopteryx (ar key-AHP-ter-icks) with feathers, hollow bones, clawed wings, fifty tiny teeth, and a long bony tail is the earliest known dinosaur that also qualifies as a bird. This spring, the Field Museum is becoming one of the few places on Earth to see a real Archaeopteryx fossil.

“Archaeopteryx is arguably the most important fossil ever discovered. It transformed how scientists see the world, by providing strong support for Darwin’s theory of evolution”, said Field Museum President and CEO Julian Siggers, PhD. “This is the Field Museum’s most significant fossil acquisition since SUE the T. rex, and we’re thrilled to be able to study ‘the Chicago Archaeopteryx’ and to share it with our visitors”.

Only a dozen other Archaeopteryx specimens have been found; most of them are in Europe. The only other Archaeopteryx in the United States is in Thermopolis, Wyoming. “As the only Archaeopteryx specimen in a major natural history museum in the Western Hemisphere, we hope this fossil will become an ambassador for paleontology”, said Siggers. “By joining the Field’s world-famous collection of fan-favorite dinosaurs, including SUE the T. rex, the Chicago Archaeopteryx cements our city as the greatest place in the U.S. to be a dinosaur fan”.

All Archaeopteryx specimens come from a fossil deposit in southern Germany called the Solnhofen Limestone. This particular specimen was found by a private fossil collector prior to 1990, and has been in private hands since 1990. A coalition of supporters helped the Field Museum procure it; it arrived at the museum in August 2022.

“When the specimen arrived, it was still unprepared, meaning that most of the skeleton was obscured by a top layer of rock. We weren’t sure how complete it was—when we X-rayed the fossil slab and saw that the fossil inside was nearly 100% complete, we cheered”, said Jingmai O’Connor, PhD, the Field’s associate curator of fossil reptiles.

The fossil’s unprepared state provided a unique opportunity for the Field Museum. “When a fossil is prepared for the commercial fossil industry, sometimes the physical beauty of the specimen is prioritized over the scientific details. But since the Field Museum’s fossil preparators Akiko Shinya and Connie Van Beek led the project, they preserved all sorts of fine details that are invaluable to scientists using this fossil for research”, said O’Connor.

O’Connor is renowned for her work on fossil birds, but she never imagined she’d be able to work on an Archaeopteryx. “I’d say that working on it was a dream come true, but I didn’t even think something so special was worth dreaming of,” she said. O’Connor has already begun studying the Chicago Archaeopteryx, and her forthcoming work is based on never-before-seen details of the animal’s skeleton, especially its skull. “This is one of the most complete, best-preserved Archaeopteryx ever found, and thanks to Akiko and Connie’s work, it’s the best-prepared”, said O’Connor.

Quotes from elected officials

“Illinois has always been a home for those looking to learn, explore, and expand their horizons— and I’m so glad that now, visitors to the Field Museum will be able to do so by learning about Archaeopteryx”, said Governor JB Pritzker. “This acquisition is another jewel in the Field’s fossil collection, and I’m certain this one-of-a-kind experience will bring visitors and curious minds to Chicago to explore the earliest known bird”.

"The acquisition of the Archaeopteryx fossil by the Field Museum enriches our community's engagement with science and history, aligning with Cook County's goals to cultivate access to educational and cultural resources", said Cook County Board President Toni Preckwinkle. "As a former history teacher, I see this extraordinary specimen as a crucial link between the past and the present - it also illustrates the importance of investing in resources that not only educate but also inspire. As we unveil this treasure, we reaffirm our commitment to fostering Cook County as a regional hub of knowledge and discovery for all".

“We are excited to celebrate this priceless specimen and its significance in further positioning Chicago as a premier destination in the world to explore the natural sciences”, said Mayor Brandon Johnson. “We are especially appreciative of the educational programming the Field Museum is developing to ensure the Archaeopteryx enriches the experience of students and educators right here in the community”.