Discovery of Early Cretaceous (Barremian) decapod Crustacea from the Arida Formation of Wakayama Prefecture, Japan

抄録

Hoploparia sp. (Astacidea, Nephropidae) and Callianassa (s. l.) sakakuraorum sp. nov. (Thalassinidea, Callianassidae) are described from the Lower Cretaceous Arida Formation in Wakayama Prefecture, Japan. Both genera are recognized for the first time from Lower Cretaceous (Barremian) deposits of Japan. These occurrences indicate that Hoploparia and Callianassa reached Japan-the west side of the North Pacific region-by the Barremian.