Two feathered dinosaurs from northeastern china

Abstract

Current controversy over the origin and early evolution of birds centres on whether or not they are derived from coelurosaurian theropod dinosaurs. Here we describe two theropods from the Upper Jurassic/Lower Cretaceous Chaomidianzi Formation of Liaoning province, China. Although both more primitive than the earliest known avialan (bird), Archaeopteryx. These new fossils represent stages in the evolution of birds from feathered, ground- living, bipedal dinosaurs.