Enigmatic Giant Pterosaur Tracks and Associated Ichnofauna from the Cretaceous of Korea: Implication for the Bipedal Locomotion of Pterosaurs

Abstract

Enigmatic tracks and dinosaur trackways from lacustrine margin sediments of the Lower Cretaceous Haman Formation of the southern coast of Korea represent a new ichnospecies. Trackways with large, pes-only tracks with lengths up to 39 cm, characterized by elongate, subtriangular outlines, impressions of four digits and a subangular heel, are attributed to plantigrade pterodactyloids and assigned to Haenamichnus gainensis ichnosp. nov. These tracks comprise one of the largest and longest pterosaur trackways hitherto reported and provide intriguing new insight into pterosaur locomotory gait and stance, which has been the subject of a 200-year-long controversy. Associated sauropod tracks, assigned herein to Brontopodus birdi, reach 70 cm in length, are medium-gauged, and show outwardly curved digit impressions. E-W trackway alignments likely indicate shoreline trends but could possibly suggest behavioral hunting scenarios. Pes-only pterosaur tracks at this locality are another example of spoor incorrectly interpreted by creationists as the footprints of humans that coexisted with dinosaurs during the Cretaceous Period. This erroneous interpretation is popular in some circles in Korea.