Using skulls to measure the size of bird brains can help lead to a better understanding of the evolution of flight because bird skulls grow to a certain size before leaving the nest, and doesn’t continue to grow past that point. The brain, however, continues to grow until it fills almost the entire cavity, meaning that bird skulls are a good indication of brain shape and size.
The researchers’ main focus is the flocculus, which is a tiny part of the cerebellum that is in charge of integrating balance and visual signals while flying. According to Walsh, studying this part of the brain may allow them to better understand how the flocculus evolved and how this evolution might be linked to “different flying abilities” in birds, which would indicate when certain changes occurred through time.
To do this, the researchers used an ultra-sensitive computerized tomography (CT) scanner, which allowed them to study the skulls and create three-dimensional models of the brains of extinct birds.