- Science reports of Niigata University. (Geology) = Science reports of Niigata University. (Geology) (ISSN:13491237)
- vol.34, pp.49-57, 2019-03
An updated version from radiolarian zonal scheme in the 1990s for the Jurassic in Japan and the western Pacific is presented and vertical distributions of selected radiolarian species are illustrated. The major modifications are as follows: The Bipedis horiae Zone (JR0) is added below the Parahsuum simplum Zone (JR1). The base of the Bipedis horiae Zone (JR0) is defined by the last occurrence biohorizon of Haeckelicyrtium breviora Sugiyama and corresponds to the Triassic–Jurassic boundary. The base of the Parahsuum simplum Zone is dated within the Sinemurian. The Tricolocapsa plicarum Zone (JR4), Tricolocapsa conexa Zone (JR5), Stylocapsa(?) spiralis Zone (JR6), and Pseudodictyomitra primitiva Zone (JR8) are modified to the Striatojaponocapsa plicarum Zone (JR4), Striatojaponocapsa conexa Zone (JR5), Kilinora spiralis Zone (JR6), and Loopus primitivus Zone (JR8), respectively, in accordance to the change of generic assignment of zone-nominal species.