The first record of an ornithomimosaurian dinosaur from the Upper Cretaceous of Japan

Ornithomimosaurs have unusual characters among theropod dinosaurs, and many records of these animals have been reported previously from Asia and North America. However, the fossil record of ornithomimosaurs is limited and was not known from the Upper Cretaceous in Japan despite its many dinosaur discoveries. Here, the first fossil of an ornithomimosaurian dinosaur from the Upper Cretaceous in Japan is described from the Upper Formation of the Mifune Group in Kumamoto Prefecture, Southwest Japan. This new discovery indicates the existence of ornithomimosaurs in the Late Cretaceous coastal areas of East Asia under a semi-arid climate. The occurrences of ornithomimosaur fossils described here are consistent with the presence of many fossil records from a dry climate rather than the humid conditions in the Cretaceous deposits of Asian mainland today.