|Daughter taxa (time control age-window is: 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, 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
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
Parent taxon (pf_mesozoic):
This taxon: Aperture symmetrical, ranging from a low slit to a high arch at the base of the final chamber, becoming terminal in uniserial taxa.
Last occurrence (top): at top of Danian Stage (100% up, 61.6Ma, in Selandian stage). Data source: Total of range of species in this database
First occurrence (base): in upper part of Albian Stage (72% up, 104Ma, in Albian stage). Data source: Total of range of species in this database
Plot of range and occurrence data:
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
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
Heterohelicidae compiled by the pforams@mikrotax project team viewed: 20-3-2023
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