Cribrohantkenina


Classification: pf_cenozoic -> smooth non-spinose -> Hantkeninidae -> Cribrohantkenina
Sister taxa: Clavigerinella, Cribrohantkenina, Hantkenina,
Daughter taxa (blue => in age window 0-300Ma)
Cribrohantkenina inflata is distinguished from H. nanggulanensis and all other hantkeninids by the presence of one of more areal apertures in addition to the primary aperture in the final adult chamber(s). Forms possessing a deeply crenulated primary aperture but no isolated additional aperture (a condition that probably represents the transition from H. nanggulanensis) are excluded from the genus. This taxon contains some of the largest individuals among modern and fossil planktonic foraminifera, attaining shell sizes in excess of 1.0 mm.

Taxonomy

Citation: Cribrohantkenina Thalmann, 1942
Rank: Genus
Type species: Hantkenina (Cribrohantkenina) bermudezi Thalmann (by original designation; regarded by Thalmann [1942] as a junior synonym of Hantkenina inflata Howe, 1928).
Synonyms:
Taxonomic discussion: The somewhat complicated taxonomic history of this genus was discussed by Blow (1969, 1979). As argued by Barnard (1954), the presence of additional areal apertures in Cribrohantkenina alone may not warrant distinction at the generic level. However, the genus is retained here to preserve taxonomic stability because it is stratigraphically useful and universally recognized. Following Blow (1979) and Toumarkine and Luterbacher (1985), Cribrohantkenina is regarded as a monotypic genus. [Coxall & Pearson 2006]

Catalog entries: Cribrohantkenina;

Type images:

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


Wall type: Smooth, normal perforate, probably non-spinose. [Coxall & Pearson 2006]

Test morphology: Planispiral, biumbilicate, 5-
6 chambers in the final whorl, increasing rapidly in size as added; chambers polygonal or spherical and highly inflated, adult chambers extended into a hollow tubulospine, spanning the suture between chambers; multiple ‘cribrate’ aperture system.
[Coxall & Pearson 2006]

Biogeography and Palaeobiology

Biostratigraphic distribution

Geological Range:
Last occurrence (top): within Priabonian Stage (33.89-37.75Ma, top in Priabonian stage). Data source: Total of range of species in this database
First occurrence (base): within Bartonian Stage (37.75-41.15Ma, base in Bartonian stage). Data source: Total of range of species in this database

Plot of occurrence data:

Primary source for this page: Coxall & Pearson 2006 - Atlas of Eocene Planktonic Foraminifera, chapter 8, p. 225

References:

Barnard, T., (1954). Hantkenina alabamensis Cushman and some related forms. Geological Magazine, 91(5): 384-390.

Blow, W.H., (1969). Late middle Eocene to Recent planktonic foraminiferal biostratigraphy. In: Bronnimann, P. and Renz, H.H. (Editors), Proceedings of the First International Conference on Planktonic Microfossils, Geneva, 1967, Leiden, Netherlands, pp. 380-381.

Blow, W.H., (1979). The Cainozoic Globigerinida: A study of the morphology, taxonomy, evolutionary relationships and stratigraphical distribution of some Globigerinida (mainly Globigerinacea). E. J. Brill, Leiden, 1413 pp.

Coxall, H.K. & Pearson, P.N., (2006). Taxonomy, biostratigraphy, and phylogeny of the Hantkeninidae (Clavigerinella, Hantkenina and Cribrohantkenina). In: Pearson, P.N. et al. (Editors), Atlas of Eocene Planktonic Foraminifera, Cushman Foundation Special Publication 41. Allen Press, Lawrence, Kansas, pp. 213-256.

Howe, H.V., (1928). An observation on the range of the genus Hantkenina. . Journal of Paleontology, 2(1): 13-14.

Spraul, G.L., (1963). Current status of the upper Eocene foraminiferal guide fossil, Cribrohantkenina. Journal of Paleontology, 37(2): 366-370.

Thalmann, H.E., (1942). Foraminiferal genus Hantkenina and its subgenera. American Journal of Science, 240: 809-820.


Cribrohantkenina compiled by the pforams@mikrotax project team viewed: 28-4-2017

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