Daughter taxa (time control age-window is: 0-800Ma)
Eoglobigerina spiralis 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
Eoglobigerina edita 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.
Eoglobigerina eobulloides 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.
Eoglobigerina sp. Specimens which cannot be assigned to established species
Taxonomy
Citation: Eoglobigerina Morozova, 1959taxonomic rank: GenusType species: Globigerina (Eoglobigerina) eobulloides Morozova, 1959Taxonomic 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]
Distinguishing features: Parent taxon (Globigerinidae): Wall spinose, usually with 3½-6 globular chambers in final whorl, trochospiral or planispiral This taxon: Low, trochospiral test, 4-6½ globular chambers in final whorl; umbilicus small and open to the apertures of surrounding chambers.
Wall cancellate and spinose wall with spine holes along the ridges.
NB These concise distinguishing features statements are used in the tables of daughter-taxa to act as quick summaries of the differences between e.g. species of one genus. They are being edited as the site is developed and comments on them are especially welcome.
Geological Range: Last occurrence (top): at top of P2 zone (100% up, 62.3Ma, in Danian stage). Data source: Total of ranges of the species in this database First occurrence (base): within P0 zone (66.00-66.04Ma, base in Danian stage). Data source: Total of ranges of species in this database
Plot of occurrence data:
Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
Triangles indicate an event for which a precise placement has been suggested
Neptune data: This is a higher taxon page so Neptune data is not plotted. See also: customisable plot Parent: Globigerinidae
Primary source for this page: Olsson et al. 1999 - Atlas of Paleocene Planktonic Foraminifera, p. 199
References:
Hemleben, C., Mohlen, 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. gs
Koutsoukos, E. (2014). Phenotypic plasticity, speciation, and phylogeny in Early Danian planktic foraminifera. Journal of Foraminiferal Research. 44: 109-142. gs
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. gs
Olsson, R. K., Hemleben, C., Berggren, W. A. & Huber, B. T. (1999). Atlas of Paleocene Planktonic Foraminifera. Smithsonian Institution Press, Washington, DC. (85): 1-252. gs
Eoglobigerina compiled by the pforams@mikrotax project teamviewed: 16-10-2024
