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Clavihedbergella subcretacea


Classification: pf_mesozoic -> Hedbergellidae -> Clavihedbergella -> Clavihedbergella subcretacea
Sister taxa: C. amabilis, C. eocretacea, C. leckiei, C. moremani, C. moulladei, C. pauliani, C. simplex, C. simplicissima, C. subcretacea, C. subdigitata, C. sp.,

Taxonomy

Citation: Clavihedbergella subcretacea (Tappan, 1943)
Rank: Species
Basionym: Hastigerinella subcretacea
Taxonomic discussion: This species differs from B. eocenica Nuttall in the smaller size, narrower and more numerous chambers, and the more trochoid appearance. It is similar in the comparatively short chambers, for this genus, and in the even size throughout.
Hastigerinella subcretacea is a very primitive species of the genus, and shows many of the characters of Globigerina and Globigerinella, suggesting the possible origin of the genus Hastigerinella.
The genus Hastigerinella was formerly known only from the Upper Cretaceous to the Recent, and the generic range is here extended downward into the Lower Cretaceous. [copied from Chronos database]

Type images:

Original description: Hastigerinella subcretacea Tappan 1943: Test small, slightly trochoid, flattened, periphery broadly rounded; chambers numerous, increasing rapidly in size, six to seven in The last-formed volution, the later chambers much inflated and radially elongated; sutures distinctly depressed; wall calcareous, surface very finely perforate; aperture an arch at the base of the last-formed chamber and slightly ventrally placed on the periphery.

Entries in the Catalog of original descriptions: Hastigerinella subcretacea;

Geological Range:
Last occurrence (top): within P. appenninica zone (100.50-101.92Ma, top in Albian stage). Data source: [copied from Chronos database]
First occurrence (base): within P. ticinensis zone (101.92-103.94Ma, base in Albian 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

Character matrix

test outline:Stellatechamber arrangement:Trochospiraledge view:Equally biconvexaperture:Umb.-extraumbilical
umb chamber shape:Elongatecoiling axis:Very lowperiphery:N/Aaperture border:Thin lip
sp chbr shape:Elongateumbilicus:Wideperiph margin shape:Moderately roundedaccessory apertures:Relict
umbilical or test sutures:Strongly depressedumb depth:Shallowwall texture:Smoothshell porosity:
spiral sutures:Strongly depresseddiameter mm:0.42width mm:0.27breadth mm:0.1
final-whorl chambers:5.5-7.0

References:

Tappan, H., (1943). Foraminifera from the Duck Creek formation of Oklahoma and Texas. Journal of Paleontology, 17(5): 467-517.


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Clavihedbergella subcretacea compiled by the pforams@mikrotax project team viewed: 23-1-2018

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