Daughter taxa (time control age-window is: 0-800Ma)![]() | Granddaughter taxa | ||||
![]() | ![]() | P. columnata group Circular Prediscophaera species | |||
![]() | ![]() | P. cretacea group Elliptical Prediscophaera species with a diagonal cross | |||
![]() | ![]() | P. spinosa group Elliptical Prediscophaera species with an axial cross | |||
![]() | ![]() | ![]() | ![]() | Prediscosphaera sp. Specimens not identified to species level |
Taxonomy:
Farinacci & Howe catalog pages: Prediscosphaera * , Deflandrius + *
Morphology: Elliptical to circular placoliths with central area spanned by cross-bars which support tall, complexely-constructed spines. The distal shield is typically bicyclic, with a broad outer-cycle, generally constructed from 16 non-imbricating elements (V-units) and a narrow inner rim-cycle (R-units). The proximal shield is primarily formed from V-units but the R-units from a restricted cycle in the centre of the shield. The LM image is bicyclic, with the outer cycle dark and inner cycle bright.
Tags | LITHS: placolith, ca_disjunct, |
Metrics | Lith size: 0->0µm; Segments: 16->16; Data source notes: size range of included species |
Geological Range:
Last occurrence (top): at top of Maastrichtian Stage (100% up, 66Ma, in Maastrichtian stage). Data source: Total of range of species in this database
First occurrence (base): at base of Aptian Stage (0% up, 126.3Ma, in Aptian stage). Data source: Total of range of species in this database
Plot of occurrence data:
Arkhangelsky, A. D. (1912). Upper Cretaceous deposits of east European Russia. Materialien zur Geologie Russlands. 25: 1-631. gs Bown, P. R., Rutledge, D. C., Crux, J. A. & Gallagher, L. T. (1998). Early Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 86-131. gs Bramlette, M. N. & Martini, E. (1964). The great change in calcareous nannoplankton fossils between the Maestrichtian and Danian. Micropaleontology. 10(2): 291-322. gs Gartner, S. (1968). Coccoliths and related calcareous nannofossils from Upper Cretaceous deposits of Texas and Arkansas. University of Kansas Paleontological Contributions, Articles. 48 (Protista 1): 1-56. gs V O Perch-Nielsen, K. (1979d). Calcareous nannofossils from the Cretaceous between the North Sea and the Mediterranean. Aspekte der Kreide Europas, IUGS Series A. 6: 223-272. gs Perch-Nielsen, K. (1985b). Mesozoic calcareous nannofossils. In, Bolli, H. M., Saunders, J. B. & Perch-Nielsen, K. (eds) Plankton Stratigraphy. Cambridge University Press, Cambridge 329-426. gs Vekshina, V. N. (1959). Coccolithophoridae of the Maastrichtian deposits of the West Siberian lowlands. Trudyi Instituta Geologii i Geogiziki, Sibiriskoe Otlodelenie, Akademiya Nauk SSSR (Nauka) Moscow. 2: 56-81. gsReferences:
![]() |
Prediscosphaera compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 25-2-2021
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=10928 Go to Archive.is to create a permanent copy of this page - citation notes |