Truncorotaloididae


Classification: pf_cenozoic -> muricate non-spinose -> Truncorotaloididae
Sister taxa: Globoquadrinidae, Truncorotaloididae,
Daughter taxa (blue => in age window 0-300Ma) Granddaughter taxa
Test, a moderate to low trochospire; chambers ovoid shaped, generally with 4-6 chambers in final whorl, occasionally 7 or more; wall moderately to strongly muricate with moderate to strong pustule growth on umbilical shoulders surrounding aperture; aperture interiomarginal, umbilical-extraumbilical, with or without thin lip. [Olsson et al. 1999]

This monospecific genus is easily recognized by the peripheral keel that extends into blade-like projections (which we call ‘keel-spines’ as distinct from the hollow tubulospines of Hantkenina) at the midpoint of each chamber in the ultimate whorl. In contrast to similar morphologic taxa such as the benthic foraminifer Pararotalia, the genus has a normal perforate wall with short coalescing pustulose ridges surrounding the pores, thus producing a roughened or cancellate-like appearance in the adult and terminal stages.

Test small, biconvex, may have a peripheral keel; chambers, ovoid or low conical in shape, 5-6 in final whorl; wall, coarsely cancellate, praemuricate, often with a thick, encrusted pustulose layer covering the praemuricate wall; aperture, interiomarginal, umbilical-extraumbilical, a low arch bordered by a thin lip. [Olsson et al. 1999]

Strongly anguloconical chambers throughout ontogeny. Surface texture strongly pustulose (muricate) on parts of spire and umbilicus. Most species with muricocarina. [Olsson et al. 1999]

Morozovelloides n. gen. is highly convergent in morphology with some true Morozovella. It is considered in this work to be derived from Acarinina.



Test very low trochospiral, 5-6, up to 8 in some species, globular to oval chambers in last whorl that increase slowly to moderately in size; periphery moderately to distinctly lobulate; nonspinose, cancellate wall texture weakly developed; aperture an interiomarginal, umbilical-extraumbilical low to high rounded arch, bordered by a thin lip.

Taxonomy

Citation: Truncorotaloididae Loeblich and Tappan, 1961
Rank: Family
Taxonomic discussion: This family tentatively includes Acarinina, Igorina, Morozovella, and Praemurica. As discussed in "Phylogeny," there are two views among the working group members on the relationships between these genera (see Figure 5a, b). The use of this family appears appropriate, for the time being, until these differences are resolved. [Olsson et al. 1999]

Catalog entries: Truncorotaloididae;

Type images:

Short diagnosis: Test, a low to moderately elevated trochospire, with or without peripheral keel; chambers globular to conical shaped; wall cancellate to muricate, pustule growth moderate to heavy, usually around umbilical area or along a peripheral keel; aperture interiomarginal, umbilical-extraumbilical, with or without lip, may have supplementary apertures. [Berggren et al. in Olsson et al. 1999]

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, a low to moderately elevated trochospire, with or without peripheral keel; chambers globular to conical shaped; wall cancellate to muricate, pustule growth moderate to heavy, usually around umbilical area or along a peripheral keel; aperture interiomarginal, umbilical-extraumbilical, with or without lip, may have supplementary apertures. [Berggren et al. in Olsson et al. 1999]

Biogeography and Palaeobiology

Biostratigraphic distribution

Geological Range:
Last occurrence (top): within Rupelian Stage (28.09-33.89Ma, top in Rupelian stage). Data source: Total of range of species in this database
First occurrence (base): within Danian Stage (61.61-66.04Ma, base in Danian stage). Data source: Total of range of species in this database

Plot of occurrence data:

Primary source for this page: Berggren et al. 2006 - Atlas of Eocene Planktonic Foraminifera, chapter 9, p. 261

References:

Banner, F.T., (1989). The nature of Globanomalina Haque, 1956. Journal of Foraminiferal Research, 19: 171-179.

Berggren, W.A.; Pearson, P.N.; Huber, B.T. & Wade, B.S., (2006). Taxonomy, biostratigraphy, and phylogeny of Eocene Acarinina. In: Pearson, P.N. et al. (Editors), Atlas of Eocene Planktonic Foraminifera, Cushman Foundation Special Publication 41. Allen Press, Lawrence, Kansas, pp. 257-326.

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


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Truncorotaloididae compiled by the pforams@mikrotax project team viewed: 22-8-2017

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