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Heterohelicidae


Classification: pf_mesozoic -> Heterohelicidae
Sister taxa: Guembelitriidae, Heterohelicidae, Planomalinidae, Globigerinelloididae, Schackoinidae, Conoglobigerinidae, Chilostomellidae, Favusellidae, Praehedbergellidae, Hedbergellidae, Rugoglobigerinidae, Rotaliporidae, Globotruncanidae, hidden,
Daughter taxa: (blue => in age window 0-800Ma) Granddaughter taxa
planispiral -> biserial
Initially planispiral, final 1 or 2 pairs of chambers subtriangular with a short blunt spine.

Initially planispiral then biserial, chambers globular, aperture symmetrical, wall texture costate

biserial throughout
Biserial throughout, chambers globular, wall texture with irregular reticulate ornamentation

Biserial throughout, test compressed with a carinate peripheral margin

Biserial throughout, chambers with projections along the medial suture, like Pseudoguembelina, but without supplementary apertures, wall texture finely costate.

Biserial throughout, aperture symmetrically positioned, wall smooth, microperforate with irregularly scattered pustule or pore mounds

Biserial throughout, aperture symmetrically positioned, wall texture costate. 

Biserial throughout, aperture asymmetrically positioned, wall texture smooth.

Biserial throughout, secondary sutural apertures along the median suture, partially covered by flaplike projections. Test usuually costate.

Adult biserial chambers expanded such that test breadth is greater than width in side view.

biserial -> multiserial
Test flabelliform, biserial stage followed by a proliferation of chambers in the same plane. Medium to coarse costae.

Similar to Planoglobulina but separate origin. Costae low and irregular.

Test flabelliform, the 2 rows of chambers diverge leaving nonseptate central space that later is partially occupied by chamber proliferation.

Similar to Gublerina but: 1. chamber sets increasing by one chamber at a time rather than three; 2. finer costae; 3. transverse biaperturate walls in multiserial part.

Biserial or with chamber proliferation. Sutures rasied and beaded.

Test initially biserial, becomes conical with proliferation of multiple globular chambers forming a crown at top of test

biserial -> uniserial
Initially biserial, later chambers elongated and arranged in an irregular uniserial pattern

Initially biserial, later part of test uniserial, globular chambers throughout.  

Test biserial until final chamber, which becomes or shows a tendency to become uniserial

Taxonomy

Citation: Heterohelicidae Cushman 1927
Rank: Family

Original description: Test in the more primitive forms planospiral in the young,later becoming biserial, in the more specialized genera the spiral stage and even the biserial stage may be wanting and the rela-tionships shown by other characters; well calcareous, perforate, ornamentation in higher genera bilaterally symmetrical; aperture when simple, usually large for the size of the test, withoutteeth, in.some forms with apertural neck and phialine lip.

Entries in the Catalog of original descriptions: Heterohelicidae

Distinguishing features: Aperture symmetrical, ranging from a low slit to a high arch at the base of the final chamber, becoming terminal in uniserial taxa.

Geological Range:
Last occurrence (top): within Maastrichtian Stage (66.04-72.05Ma, top in Maastrichtian stage). Data source: Total of range of species in this database
First occurrence (base): within Albian Stage (100.50-112.95Ma, base in Albian 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

References:

Cushman, J. A. (1927a). An outline of a re-classification of the Foraminifera. Contributions from the Cushman Laboratory for Foraminiferal Research. 3: 1-105. gs V O

Loeblich, A. R. & Tappan, H. (1988). Foraminiferal Genera and Their Classification (Volume I-II). Van Nostrand Reinhold Co., New York. 1-1059. gs


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Heterohelicidae compiled by the pforams@mikrotax project team viewed: 26-9-2020

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Short stable page link: http://mikrotax.org/pforams/index.php?id=110282 Go to Archive.is to create a permanent copy of this page - citation notes



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