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Microhedbergella


Classification: pf_mesozoic -> Hedbergellidae -> Microhedbergella
Sister taxa: Asterohedbergella, Clavihedbergella, Costellagerina, Falsotruncana, Hedbergella, Helvetoglobotruncana, Liuenella, Microhedbergella, Muricohedbergella, Paracostellagerina, Paraticinella, Praeglobotruncana, Pseudoguembelitria, Whiteinella,
Daughter taxa: (blue => in age window 0-300Ma)









Specimens which cannot be assigned to established species

Taxonomy

Citation: Microhedbergella
Rank: Genus
Basionym: Microhedbergella renilaevis Huber and Leckie, 2011
Type species: Microhedbergella renilaevis Huber and Leckie, 2011
Taxonomic discussion: Huber and Leckie, 2011: Microhedbergella differs from Hedbergella primarily by its generally smaller size, particularly in the early species, by having a thinner shell wall (~2-3 microns) that is microperforate with a smooth surface, and by always having an apertural lip or flap. Microhedbergella resembles Praehedbergella because of its small test size, relatively thin wall and smooth wall texture, but these genera are considered as distantly related homeomorphic lineages because of the stratigraphic gap that separates species included within each of the genera

 

Type images:

Original description: Microhedbergella Huber and Leckie, 2011:

Test wall thin, microperforate, wall pores evenly distributed and variably spaced in adult chambers, surface smooth or with scattered and weakly developed pustules. Test small to moderate in size, coiled in a very low to low trochospire, spiral side evolute, umbilical side mostly involute; chambers globular, never elongated radially, increasing rapidly to moderately in size, with 3–6 in the final whorl; aperture a low interiomarginal, umbilical-extraumbilical arch bordered by a thin lip or flap that may extend partly into umbilical region.

Entries in the Catalog of original descriptions: Microhedbergella;

Distinguishing features:

Test wall thin, microperforate, surface smooth or with scattered and weakly developed pustules. Test low trochopiral, small, chambers globular, increasing rapidly to moderately in size, with 3–6 in the final whorl; aperture a low interiomarginal, umbilical-extraumbilical arch bordered by a thin lip or flap.

Geological Range:
Last occurrence (top): near top of Maastrichtian Stage (90% up, 66.6Ma, in Maastrichtian stage). Data source: Total of range of species in this database
First occurrence (base): near top of Aptian Stage (91% up, 114.2Ma, in Aptian stage). Data source: Total of range of species in this 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

Character matrix

test outline:chamber arrangement:Trochospiraledge view:aperture:Umb.-extraumbilical
umb chamber shape:coiling axis:periphery:N/Aaperture border:Thin lip
sp chbr shape:umbilicus:periph margin shape:Moderately roundedaccessory apertures:
umbilical or test sutures:umb depth:wall texture:shell porosity:Microperforate: <1┬Ám
spiral sutures:diameter mm:width mm:breadth mm:
final-whorl chambers:0.0-0.0

References:


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Microhedbergella compiled by the pforams@mikrotax project team viewed: 16-8-2018

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