A new robust enantiornithine bird from the Lower Cretaceous of China with scansorial adaptations

ABSTRACTWe describe a new enantiornithine bird, <i>Fortunguavis xiaotaizicus</i>, gen. et sp. nov, from the Lower Cretaceous lacustrine deposits of the Jiufotang Formation in northeastern China. The new taxon has a strongly dorsoventrally bowed furcula indicating that enantiornithines evolved furcular morphologies in parallel with ornithuromorphs. The new specimen has very robust limbs compared with other enantiornithines and has an unique foot morphology with metatarsal II much shorter than metatarsal IV, robust pedal digits, and strongly recurved pedal unguals. Although recurved unguals characterize Enantiornithes, the extreme curvature present in <i>Fortunguavis</i> suggests scansorial specialization in this species. These features hint at a unique ecology for this taxon and further increase the known diversity of body plans in Early Cretaceous enantiornithines.SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at http://www.tandfonline.com/UJVP.