A New Enantiornithes (Aves) from the Early Cretaceous of China

A new bird from the early Cretaceous Yixian Formation of Liaoning,China is described.This new species,Grabauornis lingyuanensis,shares several synapomorphies with the Enantiornithes.The specimen is relatively well preserved.The skeletal morphology of Grabauornis bears close resemblance to that of other Chinese members of this clade.The brachial index(the ratio between the lengths of humerus and ulna) is 0.95,which is close to the average for enantiornithine birds.It indicates that Grabauornis was a rather good flyer,and the presence of an alula in the wing further testifies to this.