Around 66 million years ago, at the conclusion of the Cretaceous Period, an asteroid impact near Mexico’s Yucatán Peninsula resulted in the extinction of all non-avian dinosaurs known to us. However, for the early ancestors of contemporary waterfowl, surviving this catastrophic event was quite straightforward, akin to how water flows off a duck’s back. The geographical position played a crucial role, as Antarctica may have offered a safe haven, shielded from the upheavals occurring in other parts of the world. Fossils indicate there was a temperate climate with abundant greenery, which could have been a nurturing ground for the initial members of the lineage that includes ducks and geese.
A recent publication in the journal Nature highlights the discovery of a significant fossil representing the oldest known modern bird—an early relative of ducks and geese that inhabited Antarctica during the same era when Tyrannosaurus rex was thriving in North America. The research was spearheaded by Dr. Christopher Torres, a National Science Foundation (NSF) Postdoctoral Fellow based at Ohio University’s Heritage College of Osteopathic Medicine.
The fossil, a nearly intact skull dated to around 69 million years ago, belongs to an extinct bird named Vegavis iaai, which was unearthed during a 2011 expedition organized by the Antarctic Peninsula Paleontology Project. This new skull features a long, pointed beak and possesses a brain shape that is distinct among all previously discovered Mesozoic birds, a time when non-avian dinosaurs and an odd assortment of early birds roamed the Earth. These characteristics align Vegavis with modern birds, providing the earliest evidence of a significant evolutionary diversification that occurred globally.
“Few birds are as likely to spark as much debate among paleontologists as Vegavis,” states lead author Dr. Torres, presently a professor at the University of the Pacific. “This fossil is going to help clarify many of those debates, particularly concerning Vegavis‘s position on the avian tree of life.”
Vegavis was initially identified two decades ago by study co-author Dr. Julia Clarke from The University of Texas at Austin, along with several colleagues. It was suggested then that it represented an early form of modern birds, potentially placed within waterfowl. However, modern bird fossils are extremely scarce prior to the end-Cretaceous extinction, and more recent investigations have questioned the evolutionary classification of Vegavis. The newly described specimen provides something that all previous fossils of this species lacked: an almost complete skull.
This new skull helps dispel previous doubts, revealing multiple traits such as the structure of the brain and beak bones that align with modern birds, specifically waterfowl. Unlike the majority of today’s waterfowl, this skull shows signs of robust jaw muscles designed to help overcome water resistance while diving to catch fish.
These cranial features support findings from other parts of the skeleton, indicating that Vegavis may have used its feet to swim and chase fish and other prey—an eating strategy that is quite different from contemporary waterfowl and resembles that of certain birds like grebes and loons.
“This fossil highlights that Antarctica holds vital insights into the earliest phases of modern bird evolution,” remarks Dr. Patrick O’Connor, a co-author of the study, a professor at Ohio University, and the director of Earth and Space Sciences at the Denver Museum of Nature & Science.
Birds found elsewhere in the world from the same period are quite unrecognizable by today’s standards. Additionally, the few locations that preserve delicate bird fossils often yield specimens so incomplete that they only provide vague indications of their identity, as was the case with Vegavis until now.
“The few sites with significant fossil records of Late Cretaceous birds, such as in Madagascar and Argentina, reveal an assortment of strange, now-extinct creatures with teeth and elongated bony tails that are only distantly related to present-day birds. There seems to have been a distinctly different evolutionary narrative unfolding in the remote regions of the Southern Hemisphere, particularly in Antarctica,” Dr. O’Connor noted.
Research is ongoing regarding how the Antarctic landmass influenced the development of modern ecosystems throughout the ages. In fact, according to study co-author Dr. Matthew Lamanna from the Carnegie Museum of Natural History, “Antarctica represents a considerable frontier for understanding life during the Age of Dinosaurs.”
Dr. Torres received support at Ohio University for three years through the NSF Postdoctoral Fellowship Program, focusing on exploring the relationship between bird diversification and survival strategies in face of extinction, by combining insights from ecology, brain structure, and other life history traits. He is now in his first year as an Assistant Professor in the Department of Biological Sciences at the University of the Pacific in Stockton, California.
“This discovery showcases the significance of scientific research and the essential role our institution plays in expanding knowledge about Earth’s ancient history,” stated Lori Stewart Gonzalez, President of Ohio University. “This research enhances our comprehension of early bird evolution while highlighting the priceless contributions of OHIO graduate students and postdoctoral researchers who lead these expeditions. Through these global field and laboratory efforts, we can truly grasp the transformative changes that our planet has undergone over millions of years. This study exemplifies the practical, experiential learning that bridges STEM education with hands-on, impactful research, preparing future scientists to address upcoming challenges.”
“Large-scale initiatives like this one, engaging students and postdoctoral researchers, prepare the scientists of tomorrow to collaborate, advance scientific understanding, and tackle the significant issues our planet faces,” added Dr. O’Connor.
Additional co-authors of the study include Joseph Groenke (Ohio University), Ross MacPhee (American Museum of Natural History), Grace Musser (The University of Texas at Austin and Smithsonian National Museum of Natural History), and Eric Roberts (Colorado School of Mines). This research received funding from various NSF grants, including DBI-2010996 to Torres, ANT-1142104 to O’Connor, ANT-1141820 to Clarke, ANT-1142129 to Lamanna, and ANT-0636639 along with ANT-1142052 to MacPhee.
