Distinguishing features: Clearly bicyclic Helicolithus with symmetrical diagonal cross bars
Taxonomy:
Farinacci & Howe catalog pages: D. trabeculatus * , C. cuneatus [no catalog entry yet], D. disgregatus * , E. testaceus *
Distinguishing features: Clearly bicyclic Helicolithus with symmetrical diagonal cross bars
Morphology: Varol and Girgis (1994) applied this name to specimens <6 µm. other workers appear to differntiate it form H,. anceps based on bicylic image. The type illustration of Gorka (1957) is, as usual, highly uninformative but the type illustration of Stover (1966) shows clearly a bicyclic form.
Tags | LITHS: murolith, elliptical, CA: ca_disjunct, diagonal cross, CROSS-POLARS: rim-bicyclic, V-prominent, R-prominent, |
Metrics | Lith size: 5->8µm; Data source notes: illustrated specimens |
Geological Range:
Last occurrence (top): within Late Maastrichtian Substage (66.04-69.91Ma, top in Maastrichtian stage). Data source: Burnett 1998
First occurrence (base): within Late Aptian Substage (112.95-122.98Ma, base in Aptian stage). Data source: Bown et al. 1998
Plot of occurrence data:
Applegate, J. L. & Bergen, J. A. (1988). Cretaceous calcareous nannofossil biostratigraphy of sediments recovered from the Galicia Margin, ODP Leg 103. Proceedings of the Ocean Drilling Program, Scientific Results. 103: 293-348. gs V O Bown, P. R. (2001). Calcareous nannofossils of the Gault, Upper Greensand and Glauconitic Marl (Middle Albian-Lower Cenomanian) from the BGS Selborne boreholes, Hampshire. Proceedings of the Geologists' Association. 112: 223-236. gs Bown, P. R. (2005c). Early to Mid-Cretaceous Calcareous Nannoplankton from the Northwest Pacific Ocean, Leg 198, Shatsky Rise. Proceedings of the Ocean Drilling Program, Scientific Results. 198: 1-82. gs V O 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 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 Gale, A. S. et al. (2011). The uppermost Middle and Upper Albian succession at the Col de Palluel, Hautes-Alpes, France: An integrated study (ammonites, inoceramid bivalves, planktonic foraminifera, nannofossils, geochemistry, stable oxygen and carbon isotopes, cyclostratigraphy). Cretaceous Research. 32: 59-130. gs Górka, H. (1957). Les Coccolithophoridés du Maestrichtien supérieur de Pologne. Acta Palaeontologica Polonica. 2: 239-284. gs V O Kennedy, W. J. et al. (2000). Integrated stratigraphy across the Aptian-Albian boundary in the Marnes Bleues, at the Col de Pre _-Guittard, Arnayon (Drome), and at Tartonne (Alpes-de-Haute-Provence), France: a candidate Global Boundary Stratotype Section and Boundary Point for the base of the Albian Stage. Cretaceous Research. 21: 591-720. gs Lyul'eva, S. A. (1967). Coccolithophoridae in the Turonian strata of the Dneiper-Don Basins. Geologicheskiy Zhurnal. 27: 91-98. gs Püttmann, T. & Mutterlose, J. (2019). Calcareous nannofossils from a Late Cretaceous nearshore setting. Journal of Nannoplankton Research. S4: 81-88. gs V O Reinhardt, P. (1966b). Zur Taxonomie und Biostratigraphie des fossilen Nannoplanktons aus dem Malm, der Kreide und dem Alttertiär Mitteleuropas. Freiberger Forschungshefte. C196: 5-109. gs Roth, P. H. & Thierstein, H. R. (1972). Calcareous nannoplankton: Leg 14 of the Deep Sea Drilling Project. Initial Reports of the Deep Sea Drilling Project. 12: 546-559. gs V O Stover, L. E. (1966). Cretaceous coccoliths and associated nannofossils from France and the Netherlands. Micropaleontology. 12(2): 133-167. gs Thibault, N. (2010). Calcareous nannofossils from the boreal Upper Campanian- Maastrichtian chalk of Denmark. Journal of Nannoplankton Research. 31(1): 39-56. gs V O Varol, O. & Girgis, M. (1994). New taxa and taxonomy of some Jurassic to Cretaceous calcareous nannofossils. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen. 192: 221-253. gs Verbeek, J. W. (1977). Calcareous nannoplankton biostratigraphy of Middle and Upper Cretaceous deposits in Tunisia, southern Spain and France. Utrecht Micropaleontological Bulletin. 16: 1-157. gs V O 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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Helicolithus trabeculatus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 6-3-2021
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