New records for Crustacea from the Arida Formation (Lower Cretaceous, Barremian) of Japan

摘要

Four new species of decapods and one new species of isopod are described from the Barremian (Lower Cretaceous) Arida Formation in Wakayama Prefecture, Japan. Xanthosia sakoi new species (Brachyura, Etyidae) and Palaega yamadai new species (Isopoda, Cirolanidae) represents the first record of each genus from the North Pacific realm. Xanthosia sakoi is the oldest member of this genus. Eryma nippon new species (Astacidea, Erymidae) is the first Cretaceous record for the genus Eryma from the North Pacific realm. Hoploparia natsumiae new species (Astacidea, Nephropidae) comprises the second record of this genus from the Barremian of Japan. Eomunidopsis kinokunica new species (Anómala, Galatheidae) represents the oldest record from the North Pacific realm. The systematic position of the family Etyidae is discussed and the Etyidae is elevated to full superfamily status.