Birds are the most species-rich class of tetrapod vertebrates, with over 10,000 living species distributed in diverse niches all over the world. Birds are widely used as models for investigating evolutionary and ecological questions. Resolving phylogenetic relationships of Neoavian species and estimating divergence times have been a huge challenge for scientist. One for the challenge is that it has been proposed, but not proven, that to be that there was a ‘big bang’ radiation for Neoavian birds, where many species are closely related at the dawn of the radiation. This radiation could theoretically be solved with whole genomes. However, by 2010, only three species (chicken, turkey and zebra finch) had whole genome sequences. Because of the lack of genomic data, many other avian-related questions could also not be addressed systematically.