Distinguishing features: Large (>9 µm) central structure perforate plate; rim broad.
Daughter taxa (time control age-window is: 0-800Ma)![]() | ||||
Broinsonia parca subsp. expansa Broad central plate; plate width >2 x margin width | ||||
![]() | Broinsonia parca subsp. parca Intermediate width central plate; plate width 1-2 x margin width | |||
![]() | ![]() | ![]() | Broinsonia parca subsp. constricta Narrow central plate; plate width <1 x margin width |
Taxonomy:
Farinacci & Howe catalog pages: A. parca *
Distinguishing features: Large (>9 µm) central structure perforate plate; rim broad.
Morphology: In well-preserved specimens of all three sub-species there are often 3 - 5 delicate radial bars at the base of each pore.
Tags | LITHS: placolith, elliptical, CA: plate, pores, closed, CSPH: equant, monomorphic, CROSS-POLARS: rim-bicyclic, V-prominent, R-prominent, |
Metrics | Lith size: 7->15µm; Data source notes: range of sub-species |
Geological Range:
Last occurrence (top): within Campanian Stage (72.05-83.64Ma, top in Campanian stage). Data source: Burnett 1998
First occurrence (base): within Coniacian Stage (86.26-89.77Ma, base in Coniacian stage). Data source: Burnett 1998
Plot of occurrence data:
Bukry, D. (1969). Upper Cretaceous coccoliths from Texas and Europe. University of Kansas Paleontological Contributions, Articles. 51 (Protista 2): 1-79. gs V O Burnett, J. A. (1998). Upper Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 132-199. gs V O Crux, J. A. (1980). A biostratigraphical study of Upper Cretaceous nannofossils from South-east England and North France. PhD thesis, University College London. -. gs Hattner, J. G., Wind, F. H. & Wise, S. W. (1980). The Santonian-Campanian boundary: comparison of nearshore-offshore calcareous nannofossil assemblages. Cahiers de Micropaléontologie. 3: 9-26. gs Romein, A. J. T., Willems, H. & Mai, H. (1996). Calcareous nannoplankton of the Geulhemmerberg K/T boundary section, Maastrichtian type area, the Netherlands. Geologie en Mijnbouw. 75: 231-238. gs Stradner, H. (1963). New contributions to Mesozoic stratigraphy by means of nannofossils. Proceedings of the Sixth World Petroleum Congress. Section 1 Paper 4: 167-183. gs Wise, S. W. (1983). Mesozoic and Cenozoic calcareous nannofossils recovered by DSDP Leg 71 in the Falkland Plateau region, Southwest Atlantic Ocean. Initial Reports of the Deep Sea Drilling Project. 71: 481-550. gs V OReferences:
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Broinsonia parca compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 27-2-2021
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