NEUQUENORNIS-VOLANS, A NEW LATE CRETACEOUS BIRD (ENANTIORNITHES, AVISAURIDAE) FROM PATAGONIA, ARGENTINA

A new genus and species of Late Cretaceous (Coniacian-Santonian) birds, Neuquenornis volans, is described. This new taxon is known from a fairly complete, articulated specimen from the Rio Colorado Formation of northwestern Patagonia. Synapomorphies of the humerus, radius, ulna, coracoid, femur, tibiotarsus, tarsometatarsus, and thoracic vertebrae, support its allocation to the Enantiornithes. The tarsometatarsal structure of Neuquenornis refers it to the Late Cretaceous family Avisauridae. The structure of the wing and pectoral girdle of Neuquenornis indicates that it was an active flyer, an aptitude also inferred for the El Brete enantiornithines from the Upper Cretaceous Lecho Formation of northwestern Argentina. The pedal structure of Neuquenornis and Soroavisaurus from El Brete, indicates that avisaurids were capable of perching in trees.