Taxonomy:
Distinguishing features: Moderate to large Cruciplacolithus with slightly rotated (<20 degrees) cross bars that have disjunct, birefringent blocks (‘feet') where they meet the rim.
Farinacci & Howe catalog pages: C. frequens *
Search data:Tags | LITHS: placolith, elliptical, CA: ca_disjunct, diagonal cross, CSPH: equant, monomorphic, CROSS-POLARS: rim-bicyclic, V-prominent, R-prominent, |
Metrics | Lith size: 12->14µm; Data source notes: lith size from Romein 1979 |
Geological Range:
Last occurrence (top): in mid part of NP9 zone (50% up, 56.5Ma, in Ypresian stage). Data source: Perch-Nielsen 1985, Varol, (1989, fig. 12.4)
First occurrence (base): within NP4 zone (61.51-63.25Ma, base in Danian stage). Data source: [PRB rough estimate]
Plot of occurrence data:
Bown, P. R. (2005d). Palaeogene calcareous nannofossils from the Kilwa and Lindi areas of coastal Tanzania (Tanzania Drilling Project 2003-4). Journal of Nannoplankton Research. 27(1): 21-95. gs V O Bown, P. R. (2010). Calcareous nannofossils from the Paleocene/Eocene Thermal Maximum interval of southern Tanzania (TDP Site 14). Journal of Nannoplankton Research. 31(1): 11-38. gs V O Bown, P. R. (2016). Paleocene calcareous nannofossils from Tanzania (TDP sites 19, 27 and 38). Journal of Nannoplankton Research. 36(1): 1-32. gs V O Perch-Nielsen, K. (1977a). Albian to Pleistocene calcareous nannofossils from the Western South Atlantic, DSDP Leg 39. Initial Reports of the Deep Sea Drilling Project. 39: 699-823. gs V O Romein, A. J. T. (1979). Lineages in Early Paleogene calcareous nannoplankton. Utrecht Micropaleontological Bulletin. 22: 1-231. gs V O Self-Trail, J. (2011). Paleogene Calcareous Nannofossils of the South Dover Bridge core, Southern Maryland (USA). Journal of Nannoplankton Research. 32(1): 1-28. gs V O Varol, O. (1989c). Palaeocene calcareous nannofossil biostratigraphy. In, Crux, J. A. & van Heck, S. E. (eds) Nannofossils and their applications: Proceedings of the 2nd INA Conference, London 1987. British Micropalaeontological Society Publication Series. 265-310. gs V OReferences:
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Cruciplacolithus frequens compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 28-2-2021
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