EARLY ADAPTIVE RADIATION OF BIRDS - EVIDENCE FROM FOSSILS FROM NORTHEASTERN CHINA

Late Jurassic and Early Cretaceous birds from northeastern China, incl uding many complete skeletons of Confuciusornis, provide evidence for a fundamental dichotomy in the class Aves that may antedate the tempor al occurrence of the Late Jurassic Archaeopteryx. The abundance of Con fuciusornis may provide evidence of avian social behavior, Jurassic sk eletal remains of an ornithurine bird lend further support to the idea of an early separation of the line that gave rise to modern birds, Ch aoyangia, an ornithurine bird from the Early Cretaceous of China, has premaxillary teeth.