Planispiral

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Fig. 1. Chamber arrangement and apertural face. Schematic, not to scale. In part after Hottinger, 2000. A: planispiral-spiroliniform. B: planispiral-evolute and flaring, peneropliform. C: planispiral-evolute, approaching reniform, D: planispiral-involute, as in Archaias; af: apertural face; per: periphery; pst: peristome; (Hottinger, 2006; fig. 37 [1] CC/BY-NC-SA)


Definition

  • according to Hottinger (2006):

PLANISPIRAL CHAMBER ARRANGEMENT - chambers arranged in whorls where the rate of translation (net rate of movement along the growth axis to the net rate of movement away from the axis) is zero. The spiral and umbilical sides of the test are identical and symmetrical with regard to the plane of bilateral symmetry.


See also

References

Hottinger (2000), Functional morphology of benthic foraminiferal shells, envelopes of cells beyond measure. In: Lee J.J. & Hallock P. (eds.), Advances in biology of Foraminifera, Micropaleontology, New York, vol. 46, suppl. 1, p. 57-86.

Hottinger (2006), Illustrated glossary of terms used in foraminiferal research. Carnets de Géologie, Memoir 2, ISSN 1634-0744

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