Hedbergellidae


Classification: pf_cenozoic -> smooth non-spinose -> Hedbergellidae
Sister taxa: Hantkeninidae, Hedbergellidae,
Daughter taxa (blue => in age window 0-300Ma) Granddaughter taxa
Test very low trochospiral; 5-6 chambers in final whorl; chambers globular to ovoid to low conical in shape. Aperture interiomarginal, umbilical-extraumbilical, arch with narrow lip. Wall smooth, normally perforate, pustules in some species.

Test low to very low trochospiral. Chambers globular, 5-8 in final whorl. Aperture low to high arch, with a narrow lip. Umbilicus small, deep, and open to apertures of previous chambers. Normal perforate wall, smooth to heavily pustulose, nonspinose.

Test planispiral, compressed, loosely coiled, numerous chambers in final whorl, last 1-3 chambers uncoiling. Primary aperture equatorial, oval-shaped with broad lip.

Test planispirally coiled, smooth-walled, normally perforate. Aperture equatorial, asymmetrical to symmetrical in position. The primary aperture singular or bipartite, arched openings bordered by a thin lip.

Distinguished from other Eocene genera by the umbilical-extraumbilical aperture and smooth, pustulose wall, which is sometimes weakly cancellate, and has a tendency to defoliate in dissolved or recrystallized material.

Taxonomy

Citation: Hedbergellidae Loeblich and Tappan, 1961
Rank: Family
Taxonomic discussion: The vast majority of hedbergellids are represented by Cretaceous genera. Only one genus, Hedbergella, a very common form throughout the Cretaceous, survived into the Cenozoic where it gave rise to Globanomalina in the early Danian. [Olsson et al. 1999]

Catalog entries: Hedbergellidae;

Type images:

Short diagnosis: Test trochospiral with umbilical-extraumbilical aperture with a prominent lip. Apertures of earlier formed chambers remain visible around the umbilicus.

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: Test trochospiral with umbilical-extraumbilical aperture with a prominent lip. Apertures of earlier formed chambers remain visible around the umbilicus. [Olsson et al. 1999]

Biogeography and Palaeobiology

Biostratigraphic distribution

Geological Range:
Last occurrence (top): at top of Rupelian Stage (100% up, 28.1Ma, in Rupelian stage). Data source: Total of range of species in this database
First occurrence (base): at base of Maastrichtian Stage (0% up, 72.1Ma, in Maastrichtian stage). Data source: Total of range of species in this database

Plot of occurrence data:

Primary source for this page: Olsson & Hemleben 2006 - Atlas of Eocene Planktonic Foraminifera, chapter 14, p. 415

References:

Loeblich, A.R., Jr. & Tappan, H., (1961). Cretaceous planktonic foraminifera: Part I-Cenomanian. Micropaleontology, 7: 257-304.

Olsson, R.K. & Hemleben, C., (2006). Taxonomy, biostratigraphy, and phylogeny of Eocene Globanomalina, Planoglobanomalina n. gen and Pseudohastigerina. In: Pearson, P.N. et al. (Editors), Atlas of Eocene Planktonic Foraminifera, Cushman Foundation Special Publication 41. Cushman Foundation Special Publication. Allen Press, Lawrence, Kansas, pp. 413-432.


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Hedbergellidae compiled by the pforams@mikrotax project team viewed: 21-11-2017

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