Tracking the yellow dragons: Implications of Chinaʹs largest dinosaur tracksite (Cretaceous of the Zhucheng area, Shandong Province, China)

Surfaces with more than 2200 dinosaur footprints from the Huanglonggou (Yellow Dragon Valley) site near Zhucheng, in Shandong Province, were excavated for scientific study and with a view to future development as an educational site suitable for further research and tourism. Although geographically close to spectacular and historically famous Upper Cretaceous sites yielding vast bone assemblages, representing giant hadrosaurs and other dinosaurs from the Wangshi Group, the tracksite is in the Lower Cretaceous Yangjiazhuang Formation (equivalent in part to the Longwangzhuang Formation), represents an entirely different dinosaurian fauna, dominated by small theropods. In contrast to a recent pre-excavation study of a localized outcrop which identified only three theropod track morphotypes, in a sample of 135 tracks, the present study has identified at least 2000 additional tracks including those of sauropods and turtles. It is therefore possible to present a more complete interpretation of the site based on the larger and more diverse track assemblage presently exposed. Three theropod track morphotypes are identified as grallatorid morphotypes A and B, with the latter assigned to Grallator yangi comb. nov., and Corpulentapus lilasia. Tracks have been identified from at least 5 levels, of which level 4 exhibits the vast majority in an excellent state of preservation. Other recent studies, which we re-evaluate, suggest the tracks help define an ENE–WSW shoreline with the lake center to the SSE. In terms of number of tracks documented the Huanglonggou site is one of the largest dinosaur tracksites in China, or indeed in the world.