"The evolution of modern birds is still poorly understood. My recent phylogenetic results constitute the first step towards a new picture of the history of modern birds and demonstrate that the incorporation of key fossil taxa into phylogenetic analyses permits to elucidate hypotheses of relationship supported on the basis of extant taxa alone. Milner and colleagues recently investigated the brain anatomy of very ancient birds, using state-of-the-art high resolution X-ray computed tomographic (CT) analysis. These studies showed that: [1] Any reasonably complete and uncrushed fossil bird skull can be investigated with CT technology. [2] The application of CT techniques opens up a whole new set of characters for phylogenetic analysis of both fossils and extant birds. AVIAN EVOLUTION aims: [1] To use the state-of-the-art high resolution X-ray CT facility at the NHM (London) to obtain virtual endocranial casts of fossil and extant birds. [2] To use these to gain a better understanding of avian brain evolution across major avian clades, from the Cretaceous to the present. This will enable me to test the hypothesis that forebrain expansion provided modern birds with an advantage over archaic lineages at the Cretaceous–Tertiary boundary. [3] To define new phylogenetic characters of the brain and endocranium to elucidate higher-level relationships of modern birds. [4] To provide a new, solid hypothesis for the early divergences of modern birds. This project will improve our knowledge of avian brain evolution and the diversification of birds through geological time, and will be a major contribution to the understanding of the history of life on earth. Additionally, this project will provide biologists with a solid working basis for better understanding how today’s avian biodiversity might respond to environmental change and global warming. This will ultimately have an impact on conservation biology in the European Area and around the World."