A new frog (Amphibia: Anura) from the Lower Cretaceous of western Liaoning, China

Based on a nearly complete skeleton, an archaic frog is described from the Early Cretaceous Yixian Formation near Yixian, western Liaoning Province, China. The new frog shows several peculiar morphologies including the presence of a co-ossified parahyoid bone with a V-shaped configuration. Such a parahyoid was previously known only for the problematic taxon Neusibatrachus from the Lower Cretaceous of Spain. A phylogenetic analysis was performed with the inclusion of the new taxon and Neusibatrachus. This analysis suggests that the new taxon is a primitive archaeobatrachian closely related to Notobatrachus and Vieraella, while Neusibatrachus is placed as a basal member of the Pipoidea. The suggested relationships of the new frog with South American forms reveal a biogeographic enigma that cannot be resolved until there is more fossil evidence and current phylogenetic hypotheses are further evaluated.