New discoveries are reshaping our understanding of how flight evolved, and they reveal something remarkable: dinosaurs may have developed the brainpower for flight long before they ever left the ground. A team of paleontologists and neuroscientists, using cutting-edge technology and high-resolution imaging, has provided fresh evidence suggesting that some non-avian dinosaurs had brains as capable—if not more so—than early birds like Archaeopteryx. These insights come from an in-depth study published in Nature, and they are challenging long-held assumptions about how flight first appeared in the lineage that would ultimately lead to modern birds.
For many years, Archaeopteryx has occupied a pivotal role in evolutionary biology. Often described as a transitional fossil, it was seen as the “halfway point” between feathered, ground-dwelling dinosaurs and the sky-soaring birds we know today. Its fossilized remains, discovered in the limestone quarries of Germany in the 19th century, have been studied for over a century as the prototypical example of an evolutionary bridge species. It possessed feathers, wings, and other features associated with birds, but it also retained many dinosaur-like characteristics, such as teeth and a long bony tail. Yet, what made Archaeopteryx truly fascinating was its brain. It was relatively large for its body size, and its neurological structure seemed advanced enough to support the complex behavior required for flight.
But now, this new research is rewriting that narrative. Led by Amy Balanoff, a research associate at the American Museum of Natural History and postdoctoral researcher at Stony Brook University, the team used high-resolution CT scanning to peer inside the skulls of not just Archaeopteryx, but also a diverse collection of non-avian dinosaurs and modern birds. These scans allowed the researchers to create detailed 3-D digital models of the interior of the braincases—essentially virtual endocasts—that reveal the relative size and structure of various brain regions.
What they found was surprising. According to Balanoff, “Archaeopteryx has always been set up as a uniquely transitional species between feathered dinosaurs and modern birds, a halfway point. But by studying the cranial volume of closely related dinosaurs, we learned that Archaeopteryx might not have been so special.” In other words, some of its non-avian dinosaur cousins had brains that were just as large—or even larger—in proportion to their bodies, raising the possibility that the neurological capacity for flight evolved before actual flight itself.
One of the main findings centers on the concept of brain hyperinflation. In modern birds, the brain is relatively large compared to body size, especially in the forebrain. This enlargement supports enhanced vision, coordination, and motor control—all essential abilities for flight. It had long been assumed that this trait emerged with birds. However, the new study indicates that hyperinflated brains were already present in certain groups of non-avian dinosaurs, particularly within the oviraptorosaurs and troodontids, both of which are thought to have been highly intelligent for dinosaurs.
The research team conducted their work across several major institutions, including the University of Texas, Ohio University, Stony Brook University, and the American Museum of Natural History. Using advanced CT scanners, they generated high-resolution images of the skulls of over two dozen specimens, ranging from modern birds to Archaeopteryx to tyrannosaurs. By virtually reconstructing the interiors of these skulls, they could calculate the overall brain volume, and importantly, map out distinct regions of the brain, including the olfactory bulbs (related to the sense of smell), the cerebrum, the optic lobes (related to vision), the cerebellum, and the brain stem.
This more granular analysis provided even deeper insight. “The story of brain size is more than its relationship to body size,” said coauthor Gabriel Bever, an assistant professor of anatomy at the New York Institute of Technology. “If we also consider how the different regions of the brain changed relative to each other, we can gain insight into what factors drove brain evolution as well as what developmental mechanisms facilitated those changes.“
What the team discovered was that Archaeopteryx wasn’t uniquely positioned in the evolutionary transition from non-avian dinosaurs to birds—at least not when it came to brain size. Several of the non-avian dinosaurs they examined had brain volumes that exceeded those of Archaeopteryx relative to their body size. In fact, some of these dinosaur species already suspected of being flight-capable, such as members of the troodontid family, possessed brains that were as neurologically sophisticated as early birds.
This finding is crucial because it suggests that the neurological groundwork for flight was in place before the physical adaptations for powered flight evolved. In evolutionary terms, this could mean that these dinosaurs had the sensory and motor control abilities necessary for aerial behavior, whether that took the form of gliding, leaping, or flapping flight. “If Archaeopteryx had a flight-ready brain, which is almost certainly the case given its morphology, then so did at least some other non-avian dinosaurs,” Balanoff explained.
But the study didn’t stop there. The researchers also looked at a specialized brain structure known as the wulst, which in modern birds plays a key role in processing sensory information and motor control, both essential for flight. They identified a subtle indentation in the digital brain cast of Archaeopteryx that might correspond to the wulst. However, they did not find a similar structure in the larger-brained non-avian dinosaurs, which presents an intriguing puzzle. Why would Archaeopteryx have this neurological feature while other dinosaurs with potentially better-developed brains did not? It’s a question that could reshape how we think about the evolution of bird flight and brain specialization.
The implications of this research are profound. For decades, paleontologists have debated the order in which different features of birds evolved. Feathers, once thought unique to birds, are now known to have appeared in many non-avian dinosaurs. Likewise, features like wishbones (furculae), which are important for flight mechanics, were present in non-flying dinosaurs as well. Now, we can add “bird-like” brains to the list of traits that existed well before the first true birds took wing.
This research also feeds into larger questions about how flight evolved. While we tend to think of flight as an “all or nothing” adaptation, the reality is far more complex. Flight likely evolved in incremental stages, beginning with behaviors like gliding from tree to tree, flapping to gain lift during running, or using wings for balance and maneuverability on the ground. Each of these behaviors would have required increasingly sophisticated neurological control, which these findings suggest was already in place among several non-avian dinosaur groups.
Moreover, the results have significant implications for our understanding of brain evolution more broadly. Modern birds are often regarded as highly intelligent animals, capable of complex problem-solving, tool use, and even abstract thought. This intelligence is, in part, due to their large and complex brains, but the new study suggests that the roots of this neurological sophistication go much deeper into their dinosaur ancestry than previously believed.
As researchers continue to uncover more fossil evidence and apply new technologies like high-resolution CT scanning, we can expect even more surprising revelations about the evolutionary history of birds and their dinosaur relatives. The current study opens exciting avenues for further research, particularly in understanding how specific brain regions evolved and what this means for the behavioral capabilities of dinosaurs.
For now, this discovery forces us to rethink one of the most iconic transitions in the history of life on Earth. It suggests that flight, one of nature’s most astonishing innovations, did not suddenly appear in birds, but was instead the culmination of a long and complex evolutionary process, one that began with dinosaurs who had already evolved the brainpower necessary for the skies.