pforams@mikrotax - Hantkenina primitiva pforams@mikrotax - Hantkenina primitiva

Hantkenina primitiva

Classification: pf_cenozoic -> Hantkeninidae -> Hantkenina -> Hantkenina primitiva
Sister taxa: H. nanggulanensis, H. alabamensis, H. primitiva, H. compressa, H. australis, H. dumblei ⟩⟨ H. lehneri, H. liebusi, H. mexicana, H. singanoae, H. sp.


Citation: Hantkenina primitiva Cushman & Jarvis 1929
taxonomic rank: Species
Basionym: Hantkenina alabamensis primitiva
Taxonomic discussion: Hantkenina primitiva is a variable form representing the trend in some late middle and late Eocene hantkeninids for the shell to become more evolute and for the tubulospines to form later in ontogeny (i.e. the early final whorl chambers genuinely lack tubulospines and are not broken-off, as is more commonly the case in hantkeninids). Blow (1979) regarded this feature as ‘regressive’ or ‘phylogerontic’, recapitulating what he considered to be the ancestral Pseudohastigerina condition. In contrast to Blow, we consider Hantkenina to be a monophyletic clade that evolved from the Clavigerinella group rather than Pseudohastigerina (Coxall and others, 2003), and therefore suggest these characters are the result of changes in the timing of developmental processes.
Some forms displaying a reduced number of tubulospines are significantly smaller than the holotype specimen (0.20-30 mm). These ‘dwarf’ morphotypes tend to have a total of only 8-9 chambers, compared to the usual 10-13 chambers that make up the shells of most species of Hantkenina (Coxall, 2000). It is possible that these represent juvenile stages; however, we note that small forms are most common in the upper middle and upper Eocene and mainly occur in continental shelf environments, e.g., Ecuador (Hofker, 1956), New Zealand and the New Jersey, suggesting that this form is a distinctive variety with particular oceanographic preferences. Under this taxonomy H. primitiva is retained in the strict sense (H. primitiva sensu stricto) outlined in the original description and exemplified by the holotype, but it also includes the dwarf variety (H. primitiva sensu lato). The dwarf variety may prove to be of paleoenvironmental significance. [Coxall & Pearson 2006]

Catalog entries: Hantkenina alabamensis primitiva

Type images:

Distinguishing features:
Parent taxon (Hantkenina): Final chambers with tubulospines
This taxon: Like H. compressa but tubulospines absent on early adult chambers and test generally smaller.

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.


Planispiral, biumbilicate, laterally compressed, somewhat evolute, often small for the genus; 5-7 closely appressed, rounded or polygonal chambers in the adult whorl, increasing steadily in size as added; peripheral outline is continuous or somewhat angular; first 1-3 chambers of the adult whorl are rounded, commonly pustulose and lack a tubulospine; final 2-5 chambers only are extend into hollow tubulospines; aperture is an equatorial arch, pinched laterally into a narrow slit, flaring at the base into lateral lobes, bordered by a wide imperforate lip; tubulospines positioned at or very close to the anterior chamber edge, usually spanning the suture between adjacent chambers and partially contacting the posterior wall of the adjacent youngest chamber, arising sharply from the supporting chamber; slender and tapering to a point, inclined forward in the direction of coiling. [Coxall & Pearson 2006]

Wall type:
Smooth, normal perforate and probably nonspinose; tubulospines imperforate, smooth or with fine striations. [Coxall & Pearson 2006]

Maximum diameter (excluding tubulospines) 200-400 µm. [Coxall & Pearson 2006]

Character matrix
test outline:Subcircularchamber arrangement:Planispiraledge view:Compressedaperture:Equatorial
sp chamber shape:Subtriangularcoiling axis:N/Aperiphery:Tubulospinesaperture border:Thick lip
umb chbr shape:Subtriangularumbilicus:Wideperiph margin shape:Subangularaccessory apertures:None
spiral sutures:Moderately depressedumb depth:Shallowwall texture:Smoothshell porosity:Finely Perforate: 1-2.5µm
umbilical or test sutures:Moderately depressedfinal-whorl chambers:5-7 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology

Geographic distribution

Global, most common in shelf environments and at the periphery of the hantkeninid latitudinal range. H. primitiva sometimes dominates otherwise impoverished planktonic foraminiferal assemblages. [Coxall & Pearson 2006]
Aze et al. 2011 summary: Cosmopolitan, most common in shelf environments; based on Coxall & Pearson (2006)

Isotope paleobiology
No data available. [Coxall & Pearson 2006]
Aze et al. 2011 ecogroup 3 - Open ocean thermocline; based on comparison with other species of the genus.

Phylogenetic relations
Hantkenina primitiva may have evolved from H. compressa at the base of Zone E13. [Coxall & Pearson 2006]

Most likely ancestor: Hantkenina compressa - at confidence level 4 (out of 5). Data source: Coxall & Pearson (2006) fig 8.1.

Biostratigraphic distribution

Geological Range:
Notes: Base of Zone E13 to the Eocene/Oligocene boundary. [Coxall & Pearson 2006]
Last occurrence (top): at top of E16 zone (100% up, 33.9Ma, in Priabonian stage). Data source: Coxall & Pearson (2006) fig 8.1
First occurrence (base): at base of E12 zone (0% up, 40.4Ma, in Bartonian stage). Data source: Coxall & Pearson (2006), fig. 8.1

Plot of occurrence data:

Primary source for this page: Coxall & Pearson 2006 - Eocene Atlas, chap. 8, p. 250


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. 2: 1-1413. gs

Brönnimann, P. (1950b). The Genus Hantkenina Cushman in Trinidad and Barbados, B. W. I. Journal of Paleontology. 24(4): 397-420. gs

Coccioni, R. (1988). The genera Hantkenina and Cribrohantkenina (Foraminifera) in the Massignano section (Ancona, Italy),: Ancona II. In, Premoli Silva, I., Coccioni, R. & Montanari, A. (eds) The Eocene-Oligocene Boundary in the Marche-Umbria Basin (Italy). International Subcommission on Paleogene Stratigraphy, Special Publication II . 81-96. gs

Coxall, H. K. & Pearson, P. N. (2006). Taxonomy, biostratigraphy, and phylogeny of the Hantkeninidae (Clavigerinella, Hantkenina and Cribrohantkenina). In, Pearson, P. N., Olsson, R. K., Hemleben, C., Huber, B. T. & Berggren, W. A. (eds) Atlas of Eocene Planktonic Foraminifera. Cushman Foundation for Foraminiferal Research, Special Publication . 41(Chap 8): 213-256. gs O

Coxall, H. K. (2000). Hantkeninid planktonic foraminifera and Eocene palaeoceanographic change. In, p264 (ed.) . PhD thesis, University of Bristol 1-264. gs

Coxall, H. K., Huber, B. T. & Pearson, P. N. (2003). Origin and morphology of the Eocene planktonic foraminifera Hantkenina. Journal of Foraminiferal Research. 33: 237-261. gs

Cushman, J. A. & Jarvis, P. W. (1929). New foraminifera from Trinidad. Contributions from the Cushman Laboratory for Foraminiferal Research. 5: 6-17. gs

Hofker, J. (1956e). Tertiary foraminifera of coastal Ecuador; Part II - Additional notes on the Eocene species. Journal of Paleontology. 30(4): 891-958. gs

Pearson, P. N. & Wade, B. S. (2015). Systematic taxonomy of exceptionally well-preserved planktonic foraminifera from the Eocene/Oligocene boundary of Tanzania. Cushman Foundation for Foraminiferal Research, Special Publication. 45: 1-85. gs

Wade, B. S., Aljahdali, M. H., Mufrreh, Y. A., Memesh, A. M., AlSoubhi, S. A. & Zalmout, I. S. (2021). Upper Eocene planktonic foraminifera from northern Saudi Arabia: implications for stratigraphic ranges. Journal of Micropalaeontology. 40: 145-161. gs O


Hantkenina primitiva compiled by the pforams@mikrotax project team viewed: 3-3-2024

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