Confuciusornithidae is an extinct family of pygostylian avialans known from the Early Cretaceous, found in northern China. They are descended from theropod dinosaurs and appeared about 27 million years after the genus Archaeopteryx, the first discovered transitional dinosaur between dinosaurs and birds. They are commonly placed as a sister group to Ornithothoraces, a group that contains all extant birds along with their closest extinct relatives. Confuciusornithidae consists of four genera, with type-specimens possessing both shafted and non-shafted (downy) feathers. They are also noted for their distinctive pair of ribbon-like tail feathers of disputed function.