The phylogenetics and biogeography of the following four groups of unrelated terrestrial non-passerine birds, that have endemics in both the south-west and north-east arid-zone lowlands (and Sahel), and which also encompass taxa with differing habitat tolerances, mobility and life-history traits, were examined: the bustards (Otididae), sandgrouse (Pteroclidae), coursers (Glareolidae) and Stone Partridge (Ptilopachus). Another aim of this research is to use insights from the evolutionary relationships of these families to assess the current state of their taxonomy, as well as to assess character evolution and other life history attributes (including evolution of their mating systems).