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Muricohedbergella kyphoma


Classification: pf_mesozoic -> Hedbergellidae -> Muricohedbergella -> Muricohedbergella kyphoma
Sister taxa: M. almadenensis, M. angolae, M. astrepta, M. atlantica, M. blakensis, M. crassa, M. delrioensis, M. flandrini, M. hoelzli, M. holmdelensis, M. implicata, M. kyphoma, M. loetterli, M. monmouthensis, M. planispira, M. portsdownensis, M. praelibyca, M. rosebudensis, M. sliteri, M. wondersi, M. sp.,

Taxonomy

Citation: Muricohedbergella kyphoma (Hasegawa, 1999)
Rank: Species
Basionym: Hedbergella kyphoma

Type images:

Original description: Diagnosis.- A low trochospiral species of Hedbergel/a with last four chambers umbilically shifted, compressed, and spirally elongate. Umbilicus narrow, sutures of last four chambers slightly curved.

Description.-Test of medium size, initially very low trochospiral, later becoming medium trochospiral, equatorial periphery lobulate; chambers initially globular, later slightly compressed and spirally elongated, 11 to 14 in all arranged into 2.5 to 3 whorls, enlarging gradually in size as added except for last 3 or 4 which enlarge irregularly, 6 or 7 in last whorl, last 3 or 4 characteristically elongated, compressed and shifted toward umbilicus, last chamber variable in size and shape; sutures initially radial and depressed on dosal side except for last 3 or 4 chambers in which they are curved, slightly curved and depressed on ventral side; coiling axis initially stable, later rapidly tilted for last 3 or 4 chambers, as a result, initial umbilicus occasionally being covered by last 3 or 4 chambers; umbilicus shallow, very narrow, less than 1/5 of maximum diameter of test; primary aperture bordered by a narrow lip, interiomarginal, umbilical-extraumbilical, extending to periphery; wall calcareous, surface poorly ornamented.

Entries in the Catalog of original descriptions: Hedbergella kyphoma

Geological Range:
Last occurrence (top): in mid part of H. helvetica zone (51% up, 93Ma, in Turonian stage). Data source:
First occurrence (base): in mid part of R. cushmani zone (49% up, 95Ma, in Cenomanian stage). Data source:

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:Lobatechamber arrangement:Trochospiraledge view:aperture:Umbilical-extraumbilical
sp chamber shape:Globularcoiling axis:Low-moderateperiphery:aperture border:Thin lip
umb chbr shape:umbilicus:periph margin shape:accessory apertures:
spiral sutures:Moderately depressedumb depth:Shallowwall texture:shell porosity:
umbilical or test sutures:Moderately depressedfinal-whorl chambers:6.0-7.0 N.B. These characters are used for advanced search. N/A - not applicable

References:

Hasegawa, T. (1999). Planktonic foraminifera and biochronology of the Cenomanian-Turonian (Cretaceous) sequence in the Ohyubari area, Hokkaido, Japan. Paleontological Research, Tokyo. 3: 173-192. gs


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Muricohedbergella kyphoma compiled by the pforams@mikrotax project team viewed: 28-9-2020

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Short stable page link: http://mikrotax.org/pforams/index.php?id=110369 Go to Archive.is to create a permanent copy of this page - citation notes



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