David Dufeau, a graduate student from Ohio University, spent a few days at the UCMP this July, studying the development and evolution of the middle-ear sinuses in archosaurs — birds and crocodilians. He explains that the sinuses in these animals were so greatly expanded that they completely surrounded the braincase. By understanding these super-sized sinuses in the archosaurs, David hopes to infer something about the nature of auditory receptivity. Maybe the sinuses expanded as adaptations for hearing in terrestrial and aquatic habitats. David can look at the sinuses in fossilized skulls, but he has no way of knowing whether these animals suffered from middle ear infections or terrible sinus headaches.