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Hedbergella mitra


Classification: pf_mesozoic -> Hedbergellidae -> Hedbergella -> Hedbergella mitra
Sister taxa: H. aptiana, H. bizonae, H. bollii, H. compacta, H. excelsa, H. gorbachikae, H. handousi, H. hexacamerata, H. hispaniae, H. infracretacea, H. kuhryi, H. kuznetsovae, H. labocaensis, H. luterbacheri, H. maslakovae, H. mitra, H. modesta, H. occulta, H. praelippa, H. praetrocoidea, H. primare, H. quadricamerata, H. roblesae, H. ruka, H. semielongata, H. sigali, H. similis, H. speetonensis, H. tardita, H. tatianae, H. trocoidea, > >>

Taxonomy

Citation: Hedbergella mitra (Banner and Desai, 1988)
Rank: Species
Basionym: Blefuscuiana mitra
Taxonomic discussion: This species is probably restricted to the Aptian sediments. Its stratigraphical range is hard to be traced from the original report by Banner and Desai (1988, p.164-165). [copied from Chronos database]

Type images:

Original description: The test is a low trochospire with five to six chambers in each of three whorls. The spiral side is evolute and flat; the chambers are normally subglobular, only the last one or two becoming radially subovoid and with increasingly depressed sutures. The intercameral sutures are subradial on both the spiral and umbilical sides. The umbilicus has a breadth equal to about 20% of the test diameter. The aperture is a low arch extending from the umbilicus to the periphery of the previous whorl and extending over it into the spiral suture in the last formed chamber; the aperture has a porticus extending from the umbilicus (where it is broadest) to the periphery but not beyond it. The surface of the test is smooth and microperforate (external perforations about 0.6 microns in diameter); a narrow imperforate zone may be present in the spiral suture where the aperture encroaches on to the spiral side.

Entries in the Catalog of original descriptions: Blefuscuiana mitra

Geological Range:
Last occurrence (top): within L. cabri zone (123.89-125.71Ma, top in Aptian stage). Data source: [copied from Chronos database]
First occurrence (base): within L. cabri zone (123.89-125.71Ma, base in Aptian stage). Data source: [copied from Chronos database]

Plot of occurrence data:

Dec 2017 - Plotting of Neptune data has been re-enabled on the Mesozoic pages following revision of the age-models in Neptune. The data is, however, still very sparse for the Early Cretaceous

  • (NB There is no histogram as there are no occurrence records for the taxon in the Neptune database) Parent: Hedbergella

    Character matrix

    test outline:Lobatechamber arrangement:Trochospiraledge view:Spiroconvexaperture:
    sp chamber shape:Globularcoiling axis:Very lowperiphery:N/Aaperture border:Thin lip
    umb chbr shape:Globularumbilicus:Wideperiph margin shape:Broadly roundedaccessory apertures:Relict
    spiral sutures:Moderately depressedumb depth:Shallowwall texture:Smoothshell porosity:Microperforate: <1┬Ám
    umbilical or test sutures:Moderately depressedfinal-whorl chambers:5.0-6.0 N.B. These characters are used for advanced search. N/A - not applicable

    References:

    Banner, F. T. & Desai, D. (1988). A review and revision of the Jurassic-Early Cretaceous Globigerinina,with especial reference to the Aptian assemblages of Speeton (North Yorkshire, England). Journal of Micropalaeontology. 7: 143-185. gs


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    Hedbergella mitra compiled by the pforams@mikrotax project team viewed: 27-2-2020

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    Short stable page link: http://mikrotax.org/pforams/index.php?id=110252 Go to Archive.is to create a permanent copy of this page - citation notes



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