Laguncula dorotheae


Classification: Mesozoic -> Heterococcoliths inc sedis -> globular inc sedis -> Laguncula -> Laguncula dorotheae
Sister taxa: L. dorotheae, L. montrisouensis, L. sp.,

Distinguishing features: Small murolith coccoliths with large globular, hollow spines constructed from interlocking rhombiform elements.


Taxonomy:

Citation: Laguncula dorotheae Black, 1971
Rank: Species
Variants: Laguncula pitcherensis Rai (2006) - smaller form

Farinacci & Howe catalog pages: L. dorotheae * , L. pitcherensis *

Distinguishing features: Small murolith coccoliths with large globular, hollow spines constructed from interlocking rhombiform elements.


Morphology remarks: Rare and rather sporadically recorded. Wind & Cepek (1979) reported similar forms from the Valanginian-Hauterivian of DSDP Site 397A (northwest African margin), but their illustrations show larger basal coccolith rims and slightly more elongate distal processes. They are also considerably older than other records of this taxon.

Size: Diameter of spine 4.4-6.4 µm.

Search data:
Tagsmurolith, circular, cylindrical, hollow, CA: process,
MetricsLith size: 5->9µm;
Data source notes: illustrated specimens (diameter)
Sources: illustrated specimens (diameter)
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): within Early Cenomanian Substage (96.24-100.50Ma, top in Cenomanian stage). Data source: Bown et al. 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:

References:

Black, M. (1971b). Problematical Microfossils from the Gault Clay. Geological Magazine. 108(4): 325-327. 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

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

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

Wind, F. H. & Cepek, P. (1979). Lower Cretaceous calcareous nannoplankton from DSDP Hole 397A (northwest African Margin). Initial Reports of the Deep Sea Drilling Project. 47A: 221-235. gs V O

Wise, S. W. & Wind, F. H. (1977). Mesozoic and Cenozoic calcareous nannofossils recovered by DSDP Leg 36 drilling on the Falkland Plateau, south-west Atlantic sector of the Southern Ocean. Initial Reports of the Deep Sea Drilling Project. 36(269-491): -. gs V O


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Laguncula dorotheae compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 18-9-2020

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Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=10551 Go to Archive.is to create a permanent copy of this page - citation notes



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