掛川層群土方層(鮮新-更新統)産の化石クモヒトデ

概要

論文の詳細を見る
Over 500 fossil ophiuroid individuals were collected from a narrow stratigraphic interval of the Hijikata Formation (Plio-Pleistocene, Kakegawa Group) in the Kakegawa area of Shizuoka Prefecture, central Japan. The age of the fossil-bearing beds is close to the Plio-Pleistocene boundary. The species we discriminated include four species definitely referable to modern species, one species most probably referable to a modern species and one indeterminate species of the family Amphiuridae. These identified species are Ophiura sarsii LUTKEN, 1855,Ophiozonella longispina (CLARK, 1908), Stegophiura sterea (CLARK, 1908) (Ophiuridae); Ophiochiton fastigatus LYMAN, 1878 (Ophiochitonidae); Ophiophthalmus sp. cf. O. hylacanthus (CLARK, 1911) (Ophiacanthidae); an indeterminate species of the family Amphiuridae. The Hijikata specimens of Ophiura sarsii are the oldest fossil forms known, and Ophiozonella longispina, Stegophiura sterea and Ophiochiton fastigatus were previously unknown in the fossil record.
国立科学博物館の論文
1996-12-22