Eoglobigerina


Classification: pf_cenozoic -> spinose -> Globigerinidae -> Eoglobigerina
Sister taxa: Catapsydrax, Eoglobigerina, Globigerina, Globigerinatheka, Globorotaloides, Globoturborotalita, Guembelitrioides, Orbulinoides, Paragloborotalia, Parasubbotina, Pseudoglobigerinella, Subbotina, Turborotalita,
Daughter taxa (blue => in age window 0-300Ma)
Test with distinct elevated spire, 4½ - 5½ chambers in final whorl. Umbilicus very small, sutures on the umbilical side radial. Aperture umbilically directed, with thin discontinuous lip. Wall texture more strongly developed than in E. edita, and spine holes less numerous
Test small (<250µm) moderately elevated trochospire, 4½ to 5 (rarely up to 7) globular chambers in final whorl, increasing gradually in size; strongly lobulate peripheral margin. Aperture rounded, umbilical to slightly extraumbilical, with a narrow lip. Umbilicus small but open to the previous chambers. Weakly developed cancellate wall texture with numerous spine holes along the ridges.
Test small (<250µm) moderately elevated trochospire, 4- 4½ globular chambers, in the final whorl, increasing moderately in size. Aperture umbilical to slightly extraumbilical rounded, with narrow, slightly flaring lip. Umbilicus small but open to the previous chambers. Very weakly developed cancellate wall texture.
Specimens which cannot be assigned to established species

Taxonomy

Citation: Eoglobigerina Morozova, 1959
Rank: Genus
Type species: Globigerina (Eoglobigerina) eobulloides Morozova, 1959
Taxonomic discussion: Hemleben et al. (1991) demonstrated that Eoglobigerina had a spinose morphology, which separates it from other cancellate forms in the Danian that are nonspinose. The concept of Eoglobigerina followed herein is similar to that of previous workers except that it is emended to include the spinose character. [Olsson et al. 1999]

Catalog entries: Eoglobigerina;

Type images:

Short diagnosis: Low, trochospiral test with 10-16 chambers, 4-6½ globular chambers in ultimate whorl. Trochospire moderately to highly elevated; aperture interiomarginal, umbilical to slightly extraumbilical, a low, rounded arch bordered by a thin, narrow lip; umbilicus small and open to the apertures of surrounding chambers. Cancellate and spinose wall with spine holes situated along cancellate ridges.

NB The short diagnoses are used in the tables of daughter-taxa to act as quick summaries of the differences between e.g. species of one genus. They have initially been copied from the diagnostic characters/distinguishing features sections of the Eocene and Paleocene Atlases, they will be edited as the site is developed.

Description


Diagnostic characters: Low, trochospiral test with 10-16 chambers, 4-6½ globular chambers in ultimate whorl. Trochospire moderately to highly elevated; aperture interiomarginal, umbilical to slightly extraumbilical, a low, rounded arch bordered by a thin, narrow lip; umbilicus small and open to the apertures of surrounding chambers. Cancellate and spinose wall with spine holes situated along cancellate ridges.

Biogeography and Palaeobiology

Most likely ancestor: Muricohedbergella - at confidence level 0 (out of 5). Data source: .

Biostratigraphic distribution

Geological Range:
Last occurrence (top): near top of Danian Stage (85% up, 62.3Ma, in Danian stage). Data source: Total of range of species in this database
First occurrence (base): at base of Danian Stage (0% up, 66Ma, in Danian stage). Data source: Total of range of species in this database

Plot of occurrence data:

Primary source for this page: Olsson et al. 1999 - Atlas of Paleocene Planktonic Foraminifera, p. 199

References:

Hemleben, C.; Mhlen, D.; Olsson, R.K. & Berggren, W.A., (1991). Surface texture and the first occurrence of spines in planktonic foraminfera from the early Tertiary. Geologisch Jarhbuch, 128: 117-146.

Morozova, V.G., (1959). Stratigraphy of the Danian-Montian deposits of the Crimea according to the foraminifera. Doklady Akademii Nauk SSSR, 124(5): 1113-1115.


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Eoglobigerina compiled by the pforams@mikrotax project team viewed: 23-11-2017

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