The skull of extinct birds revealed
Birds are the most diverse clade on the planet, and the skull of the living bird is one of the most highly modified and morphologically variable regions of their skeleton. The large diversity of enantiornithine birds (a group closely related to the lineage that includes living birds) uncovered from Cretaceous age deposits around the world is considered the first major avian radiation. During the complex early evolutionary history of the modern bird, it appears many derived features of living birds evolved in parallel in other more primitive groups, and some areas of the skeleton evolved modifications before others, such as the wing and other skeletal elements important to flight. However, few comprehensive studies have been done to test this. Although many enantiornithine species are recognized, and most from the famous Jehol deposits of northeastern China, our specific knowledge of morphological variation, biology and ecology is still incomplete because the rate...