Anuran (frog) trackways from the Cretaceous of Korea

Newly discovered frog tracks from the Cretaceous of Saok Island, South Korea, represent the first report of anuran (frog) tracks from the Phanerozoic of Asia and, only the second global report of Mesozoic anuran tracks. This is also the first global report of frog track assemblages with multiple trackways from multiple stratigraphic levels. The tracks occur in fine-grained lacustrine sediments and are generally well-preserved, showing a pentadactyl pes and a tetradacyl manus typical of modern anurans. The trackways indicate hopping locomotion, also typical of modern anurans, indicating that frog foot morphology and behavior have not changed significantly since the Late Cretaceous. The trackways reveal that some trackmakers possessed the ability to leap 6-7 times body (trunk) length. The material allows for the emendation of the diagnosis of the ichnogenus Ranipes and erection of the new ichnospecies Ranipes saokensis ichnosp. nov.. Associated tracks and traces of arthropods (cf. Diplichnites) and shorebirds are characteristic of typical lacustrine margin paleoecology and the shorebird ichnofacies.