Reticulofenestra umbilicus


Classification: Coccolithophores -> Isochrysidales -> Noelaerhabdaceae -> Reticulofenestra -> R. umbilicus group -> Reticulofenestra umbilicus
Sister taxa: R. umbilicus, R. dictyoda, R. hillae, R. hampdenensis, R. hesslandii, R. moorei, R. circus, R. circus var. lata, R. wadeae, R. maceria Shafik 1989, R. oamaruensis,

Distinguishing features: Very large (>14 µm) elliptical reticulofenestrids, with delicate net


Taxonomy:

Citation: Reticulofenestra umbilicus (Levin, 1965) Martini & Ritzkowski, 1968
Rank: Species
Basionym: Coccolithus umbilicus Levin, 1965
Synonyms: Tremalithus placomorphus Kamptner (1948) = Reticulofenestra placomorpha (Kamptner 1948) Stradner in Haq 1968 [according to Perch-Nielsen 1985, p.543. The holotpe is only 13.3 µm but the nme was used for very large Reticulofenestra]

Farinacci & Howe catalog pages: Coccolithus umbilicus *

Distinguishing features: Very large (>14 µm) elliptical reticulofenestrids, with delicate net


Size: Holotype length 16.1µm.

Search data:
TagsLITHS: placolith, elliptical, CA: grill, vacant,
CSPH: spherical, monomorphic, V-UNITS: none, R-UNITS: all, c-str, distal shield, prox shield, tube, DETAILS: ca_conjunct, isogyres kinked, isogyres oblique, rim-unicyclic,
MetricsLith size: 14->20µm;
Sources: Size range from Backman & Hermelin 1986
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Notes: The first appearance of very large, >14μm, elliptical reticulofenestrids (i.e. R. umbilicus) has long been used as a distinctive stratigraphic marker (e.g. Backman & Hermelin, 1986). In the Exp. 342 material these sizes are attained by subcircular to elliptical reticulofenestrids (similar to R. wadeae and R. umbilicus) in Subzone NP15b, around 3 m.y. prior to the level typically cited for this biohorizon. Agnini et al. (2014) suggest that the use of the first common occurrence of R. umbilicus may represent a more consistent horizon, above the last occurrence of C. gigas. [Bown & Newsam 2017]
Last occurrence (top): at top of NP22 zone (100% up, 32Ma, in Rupelian stage). Data source: zonal marker (see Perch-Nielsen 1985)
First occurrence (base): within NP16 zone (40.40-42.87Ma, base in Lutetian stage). Data source: Perch-Nielsen 1985

Plot of occurrence data:

  • Histogram - Neptune occurrence data from DSDP and ODP proceedings. Pale shading <50 samples in time bin. Interpret with caution & read these notes
  • Taxon plotted: Reticulofenestra umbilicus, synonyms included - Apertapetra umbilica; Reticulofenestra hillae; Reticulofenestra umbilica; Reticulofenestra umbilica (>14 micron); Reticulofenestra umbilicus; Reticulofenestra umbilicus (>14um); Reticulofenestra umbilica; space-time plot :: Samples map :: Parent: R. umbilicus group

    References:

    Agnini, C.; Fornaciari, E.; Raffi, I.; Catanzariti, R.; Pälike, H.; Backman, J. & Rio, D., (2014). Biozonation and biochronology of Paleogene calcareous nannofossils from low and middle latitudes. Newsletters on Stratigraphy, 47: 131-181.

    Backman, J. & Hermelin, J.O.R., (1986). Morphometry of the Eocene nannofossil Reticulofenestra umbilicus lineage and its biochronological consequences. Palaeogeography Palaeoclimatology Palaeoecology, 57: 103-116.

    Bown, P.R. & Newsam, C., (2017). Calcareous nannofossils from the Eocene North Atlantic Ocean (IODP Expedition 342 Sites U1403–1411). Journal of Nannoplankton Research, 37(1): 25-60.

    Haq, B.U., (1968). Studies on upper Eocene calcareous nannoplankton from NW Germany. Stockholm Contributions in Geology, 18: 13-74.

    Kamptner, E., (1948). Coccolithen aus dem Torton des Inneralpinen Wiener Beckens. Anzeiger. Österreichische Akademie der Wissenschaften. Mathematische-Naturwissenschafliche Klasse. Wien, 157: 1-16.

    Levin, H.L., (1965). Coccolithophoridae and related microfossils from the Yazoo Formation (Eocene) of Mississippi. Journal of Paleontology, 39(2): 265-272.

    Martini, E. & Ritzkowski, S., (1968). Was ist das 'Unter-Oligozän'? Eine Analyse der Beyrich'schen und v Koenen'schen Fassung der Stufe mit Hilfe des fossilen Nannoplanktons. Nachr Akad Wiss Gottingen; II Mathematisch-Physikalische Klasse, 1968, 13: 231-250.

    Perch-Nielsen, K., (1985). Cenozoic calcareous nannofossils. In: Bolli, H.M., Saunders, J.B. and Perch-Nielsen, K. (Editors), Plankton Stratigraphy. Cambridge University Press, Cambridge, pp. 427-555.


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    Reticulofenestra umbilicus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 17-12-2018

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    Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=1189Go to Archive.is to create a permanent copy of this page - citation notes



    Comments (1)

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    Simun Ascic (Zagreb University, Croatia)
    Description says <14µm. probably should be >14 µm
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    Paul Bown (Univeristy College London, UK)
    Well spotted! Just fixed it.
    Page 1 of 1
     

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