A fossil discovery in Antarctica is rewriting bird evolution

From dinosaurs to birds: this almost intact skull fossil just discovered in Antarctica could change the history of evolution. The study, led by Pacific University (USA), identified the find which proved to be extraordinarily preserved

A stunningly well-preserved bird skull fossil has been found in Antarctica by a group of researchers led by Pacific University (USA). The stunning discovery is likely to shed new light on the evolutionary process of transformation from dinosaurs to birds.

A late cretaceous period skull

The fossil skull belongs to the extinct bird Vegavis iaai, which lived on Earth during the Late Cretaceous period, just before non-avian dinosaurs went extinct. The Cretaceous period had a duration of approximately 79 million years, and this fossil is one of the very rare three-dimensional bird skulls from that ancient era known to researchers.

Numerous fossils of Vegavis iaai had been previously discovered, like the oldest recorded vocal organ, but the new skull is providing new information—not only on this specific bird extinction but also on the origins and history of birds that exist today. Since the skull is so well preserved, researchers are able to reconstruct its shape of brain once it was inside it, giving a unique look at its anatomy.

A direct link between dinosaurs and modern birds

This fossil is particularly significant since it is the first direct evidence of a close relative of modern birds in the Late Cretaceous. It confirms that ancestors of modern birds co-existed with their non-avian dinosaur cousins. Scientists believe that Vegavis iaai is most closely related to ducks and geese today and positions it in the evolutionary group known as Anseriformes, which includes both.

Also, other scientists report that Vegavis iaai may also be distantly related to a wide range of modern bird lineages.

According to the scientists, geese and ducks today are only a fraction of the anseriform birds that existed at the time. Fossil records indicate that some ancient water birds lived similar to their modern herons and flamingos.

Decades of research providing revolutionary findings

The study highlights the incredible value of decades of research on one species. For decades, scientists have researched Vegavis fossils in Antarctica, and their findings are now reshaping the greater bird evolutionary tree.

“This new fossil has a lot to say about the early history of modern bird evolution,” says Patrick O’Connor, the study’s leader.

And that is only the beginning. Fossils of plant and animal organisms from this period in Antarctica are extremely rare, and they raise a great many more questions about the environments in which birds and other creatures evolved and diversified.

“Something rather different seems to have been happening at the farthest reaches of the Southern Hemisphere, particularly in Antarctica,” says O’Connor. “This needs a much broader study of the fossil record and climatic changes in this area over time.”

The study, funded by the National Science Foundation, appears in Nature.

Sources: EurekAlert / Nature