Decapod crustaceans from the Miocene Itsukaichi Basin, western Tokyo, Japan, including a new species of Trichopeltarion (Brachyura: Trichopeltariidae)

Abstract

Seven species of decapod crustaceans were described from the Miocene Itsukaichimachi Group based mainly upon examinations of the museum collection. Decapod fossils are stratigraphically limited to the Kosho and Tateya formations and characterized by the predominance of Callianopsis titaensis (Nagao, 1941). Five and two additional species were obtained from these formations, respectively. Trichopeltarion ryouheii, Kato n. sp. and Carcinoplax antiqua (Ristori, 1889) are the first recognized decapod species common to the adjacent Miocene Chichibu Basin in Saitama Prefecture.