The Confuciusornithidae is another small clade of primitive birds, but it is represented by hundreds of complete specimens of its best-known taxon, Confuciusornis (Early Cretaceous, China). All three known taxa of confuciusornithids were discovered in the exquisite fossil deposits of Liaoning and neighboring provinces in northeastern China.

These basal birds were closer to modern birds than was Archaeopteryx and had already shed most of the traits of non-avian dinosaurs—teeth and a long tail—that had been retained by Archaeopteryx. Confuciusornis was about the size of a crow. It had a pygo-style, or shortened tail tip composed of coalesced vertebrae, for the attachment of tail feathers, but it still retained long, curved claws on its wings—a trait considered a primitive or basal bird trait. The Confuciousornithidae share some similarities with the dromaeosaur

A Confuciusornis skeleton

Microraptor; this suggests a close relationship with that line of non-avian coelurosaurian dinosaur.

A primitive feature that Confuciusornis shared with Archaeop-teryx was found in the wings. The shoulder bones of Confuciusornis were oriented in such a way as to have prevented the kind of upstroke required for the type of flapping flight seen in modern birds. Confu-ciusornithids most certainly were adequate fliers, but they may have managed powered flight with a shallow, jolting thrust of the wings that would seem quite peculiar when compared with modern birds.

At least one specimen of Confuciusornis has been found with evidence of a last meal in its remains. In 2006, Swedish paleontologist J. Dalsatt and colleagues reported finding a specimen with fish remains in its throat. This suggests that confuciusornithids were either fish eaters or omnivorous.

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