New Insights Reveal Archaeopteryx Flew and Ran Like a Jurassic Chicken

In 1861, scientists uncovered the Archaeopteryx, a feathered dinosaur, embedded in 150-million-year-old limestone in Solnhofen, Germany. Though unrecognized at the time, this fossil—along with several others discovered later—became crucial evidence supporting evolutionary theory and confirming that birds are descendants of dinosaurs.

Archaeopteryx specimens have profoundly influenced our understanding of natural history, arguably reshaping perspectives more than any other fossil, noted Jingmai O’Connor, a paleontologist at Chicago’s Field Museum.

Over the past 164 years, researchers have meticulously examined every available Archaeopteryx fossil, striving to unravel how birds first achieved flight. Given its extensive study, one might expect the species to yield few surprises. However, a new study published recently in the journal Nature reveals previously unseen soft tissue and skeletal details from a newly analyzed specimen dubbed the Chicago Archaeopteryx. These findings illuminate why some feathered dinosaurs took to the air, even if only for brief flights.

Determining the flight capabilities of Archaeopteryx and its ecological role has long posed challenges, O’Connor explained. Most known specimens have been severely flattened by geological processes, obscuring key skeletal details. While early discoverers and many modern scientists have concluded that Archaeopteryx likely achieved some form of flight, certain anatomical features have left paleontologists seeking additional evidence.

The latest specimen, acquired by the Field Museum in 2022 and publicly displayed since 2024, enabled O’Connor’s team to address some of these anatomical uncertainties.

Upon arrival at the museum, the fossil appeared unremarkable. Its coloration blended with the surrounding rock, and most soft tissue remnants were difficult to detect, O’Connor said.

Using computed tomography scanning, researchers generated a detailed digital map of the skeleton to aid in careful excavation. They also employed ultraviolet light, which causes certain fossilized soft tissues to fluoresce due to chemical properties, enabling the team to distinguish feathers and skin textures from bone without accidental damage—a technique unavailable to 19th-century fossil preparators.

Unlike other Archaeopteryx fossils, the Chicago specimen’s bones remained preserved in three dimensions, allowing the team to better analyze the skull’s palate. This analysis revealed early evolutionary adaptations toward the more mobile skulls seen in modern birds, O’Connor noted.

A fortunate aspect of the fossilization process left the wings detached from the body, preserving them "clear and pristine," according to O’Connor. Detailed examination showed that, contrary to earlier specimens which appeared to have two layers of feathers on their wings, this Archaeopteryx had three. In modern birds, the third feather layer connects the shorter forearm to the body, forming a continuous lifting surface crucial for sustained flight.

O’Connor highlighted that the wing structure contrasts with that of other feathered non-avian dinosaurs, whose long feathers abruptly end at the elbow, serving more as ornamental features rather than functional flight surfaces.

Although the absence of a sternum suggests Archaeopteryx probably did not engage in prolonged flight, preserved toe pads on the Chicago specimen’s feet support the view that it was adept at terrestrial movement. This implies the species lived much like a Jurassic-era chicken or roadrunner—capable of short bursts of flight when necessary but primarily relying on running.

The newly identified traits significantly enhance current understanding of Archaeopteryx, directly supporting prevailing theories about its flight abilities and evolutionary position, commented Michael Pittman, a paleontologist not involved in the study.

"This research effectively underscores the value of discovering new fossils, even among specimens that have been extensively studied," he added.

O’Connor echoed this sentiment, stating, "This specimen will keep me engaged for years to come."