First record of Deltapodus tracks from the Early Cretaceous of China
Despite being widely distributed in the Middle–Late Jurassic and earliest Cretaceous of Europe and sparsely distributed in the Late Jurassic of North America, the thyreophoran ichnotaxon Deltapodus is represented largely by morphologically suboptimal material. In particular, manus tracks are poorly defined in almost all previously reported specimens, likely due to preservational factors. Nonetheless, two ichnospecies, D. brodericki and D. ibericus, have been erected based on European material. Here we report the first Chinese examples of Deltapodus from the Cretaceous of Xinjiang Uyghur Autonomous Region, China. These specimens are also the youngest unambiguous occurrence of this ichnogenus, and the second reported occurrence from Asia. The specimens have well-defined manus traces with readily identifiable traces of digits I and II, enabling their placement in a new ichnospecies: Deltapodus curriei ichnosp. nov. Although not unequivocal in all cases, Deltapodus is likely of stegosaurian affinity, given the occurrence of stegosaurian body fossils in related deposits in Xinjiang. Deltapodus tracks are far more common and widespread than Stegopodus or Apulosauripus, the only other ichnogenera with tridactyl pes prints that have been attributed to large thyreophorans.