pforams@mikrotax - Hantkenina mexicana pforams@mikrotax - Hantkenina mexicana

Hantkenina mexicana

Classification: pf_cenozoic -> Hantkeninidae -> Hantkenina -> Hantkenina mexicana
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 mexicana Cushman 1924
taxonomic rank: Species
Basionym: Hantkenina mexicana
Taxonomic discussion: We regard H. mexicana as a senior synonym of H. nuttalli Toumarkine, 1981. Various authors have used Toumarkine’s (1981) concept of H. nuttalli to represent ‘primitive-looking’ early hantkeninids with digitate chambers and stout, broad based tubulospines. Although there may be a case for distinguishing these forms we have been unable to consistently recognize these morphologic differences in populations of early hantkeninids. Moreover, the holotype of H. nuttalli (one of three H. aragonensis syntypes selected by Nuttall, 1930) does not clearly demonstrate the features claimed by Toumarkine’s (1981) description (i.e. large, inflated chambers, which taper more gradually into the terminal spines) because all the tubulospines have broken off. Therefore, following Blow (1979) we adopt a broad sense of H. mexicana to include the spectrum of early stellate hantkeninid morphologies from their origin at the base of the middle Eocene. However, we do recognize a new species transitional from Clavigerinella to Hantkenina, namely H. singanoae n. sp. (see below). [Coxall & Pearson 2006]

Catalog entries: Hantkenina mexicana, Hantkenina mexicana aragonensis, Hantkenina nuttalli

Type images:

Distinguishing features:
Parent taxon (Hantkenina): Final chambers with tubulospines
This taxon: Final chambers elongate; tubulospines centrally positioned; peripheral outline distinctly stellate. 4-5 chambers in the final whorl.

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, evolute, biumbilicate or showing a slightly raised spiral side and very shallow umbilicus; laterally compressed with 4-5 rapidly expanding chambers in the final whorl; final whorl chambers radially elongate or digitate, well separated, inflated peripherally and more compressed within the umbilical region; some specimens, including the holotype, exhibit anterior flexure of the final chamber; peripheral outline distinctly stellate; each chamber of the adult whorl extends gradually into a hollow tubulospine; aperture is a narrow, elongate equatorial arch bordered by an imperforate flaring lip, often with a crenulated and/or pustulose margin, relict apertural lips are sometimes preserved as webs along the sutures; sutures straight, becoming curved in the final stages, only partially contacting adjacent chamber; tubulospines variable in form, broad-based and stout or long and slender, positioned centrally with respect to the radial chamber axis, directed radially between anterior and posterior chamber shoulders, distal ends usually blunt and closed (although it is possible that a terminal aperture existed in life) and commonly possess terminal finger-like projections (coronet structure of Ramsay, 1962). [Coxall & Pearson 2006]

Wall type:
Smooth, normal perforate and probably nonspinose; tubulospines imperforate or with small, scattered pores, smooth or finely striated with a well-defined zone of demarcation between the tubulospines and the chamber wall. [Coxall & Pearson 2006]

Maximum diameter (excluding tubulospines) 0.5 mm, with spines 0.75 mm or more (Cushman, 1924). [Coxall & Pearson 2006]

Character matrix
test outline:Stellatechamber arrangement:Planispiraledge view:Compressedaperture:Equatorial
sp chamber shape:Inflatedcoiling axis:N/Aperiphery:Tubulospinesaperture border:Thin lip
umb chbr shape:Inflatedumbilicus:Wideperiph margin shape:Subangularaccessory apertures:Relict
spiral sutures:Moderately depressedumb depth:Shallowwall texture:Smoothshell porosity:Finely Perforate: 1-2.5µm
umbilical or test sutures:Moderately depressedfinal-whorl chambers:4-5 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology

Geographic distribution

Worldwide, restricted to low latitudes. Usually rare in open ocean sections and, thus, has been an unreliable marker for the base of planktonic foraminiferal Zone P10 (Berggren and others, 1995). Common in ODP Site 865, Mexico, US Gulf Coast and coastal Tanzania sections. [Coxall & Pearson 2006]
Aze et al. 2011 summary: Low latitudes; based on Coxall & Pearson (2006)

Isotope paleobiology
Hantkenina mexicana has higher δ18O and lower δ13C than all other co-occurring planktonic species, including the subbotinids, indicating a cold, deep, possibly sub-thermocline habitat (Coxall and others, 2000; Pearson and others, 2001). A sample analyzed by Boersma and others (1987) as H. aragonensis had isotopic ratios similar to co-occurring subbotinids. [Coxall & Pearson 2006]
Aze et al. 2011 ecogroup 4 - Open ocean sub-thermocline. Based on very light _13C and very heavy _18O. Sources cited by Aze et al. 2011 (appendix S3): Coxall et al. (2000); Pearson et al. (2001a)

Phylogenetic relations
Hantkenina mexicana evolved from H. singanoae by lengthening of the terminal protrusion into a straight, imperforate hollow tubulospine. It gave rise to H. liebusi by reduction in chamber height and a shift in the position of the tubulospines towards the anterior suture. [Coxall & Pearson 2006]

Most likely ancestor: Hantkenina singanoae - at confidence level 4 (out of 5). Data source: Coxall & Pearson (2006) fig 8.1.
Likely descendants: Hantkenina liebusi; plot with descendants

Biostratigraphic distribution

Geological Range:
Notes: Lower middle Eocene. Base of Zone E8 to E9. [Coxall & Pearson 2006]
Last occurrence (top): in upper part of E9 zone (80% up, 43.4Ma, in Lutetian stage). Data source: Wade et al. (2011), fig. 6
First occurrence (base): at base of E9 zone (0% up, 43.9Ma, in Lutetian stage). Data source: Wade et al. (2011), fig. 6

Plot of occurrence data:

Primary source for this page: Coxall & Pearson 2006 - Eocene Atlas, chap. 8, p. 242


Berggren, W. A., Kent, D. V., Swisher, I. , C. C. & Aubry, M. -P. (1995b). A revised Cenozoic geochronology and chronostratigraphy. In, Berggren, W. A., Kent, D. V., Aubry, M. -P. & Hardenbol, J. (eds) Geochronology, Time Scales and Global Stratigraphic Correlations. SEPM (Society for Sedimentary Geology) Special Publication No. 54, 129-212. gs

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

Bolli, H. M., Loeblich, A. R. & Tappan, H. (1957). Planktonic foraminiferal families Hantkeninidae, Orbulinidae, Globorotaliidae and Globotruncanidae. In, Loeblich, A. R. , Jr., Tappan, H., Beckmann, J. P., Bolli, H. M., Montanaro Gallitelli, E. & Troelsen, J. C. (eds) Studies in Foraminifera. U.S. National Museum Bulletin . 215: 3-50. gs

Brönnimann, P. (1950b). The Genus Hantkenina Cushman in Trinidad and Barbados, B. W. I. Journal of Paleontology. 24(4): 397-420. 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., Pearson, P. N., Shackleton, N. J. & Hall, M. A. (2000). Hantkeninid depth adaptation: An evolving life strategy in a changing ocean. Geology. 28: 87-90. 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

Nuttall, W. L. F. (1930). Eocene Foraminifera from Mexico. Journal of Paleontology. 4: 271-293. gs

Pearson, P. N. et al. (2001a). Warm tropical sea surface temperatures in the Late Cretaceous and Eocene epochs. Nature. 413: 481-487. gs

Raju, D. S. N. (1968). Eocene-Oligocene planktonic foraminiferal biostratigraphy of Cauvery Basin, South India. Memoir of the Geological Society of India. 2: 286-299. gs

Ramsay, W. R. (1962). Hantkeninidae in the Tertiary rocks of Tanganyika. Contributions from the Cushman Foundation for Foraminiferal Research. 13(3): 79-89. gs

Rey, M. (1939). Distribution stratigraphique des Hantkenina dans le Nummulitique du Rharb (Maroc). Bulletin de la Société Géologique de France. 5: 321-341. gs

Rögl, F. & Egger, H. (2011). A new planktonic foraminifera species (Hantkenina gohrbandti nov. spec.) from the middle Eocene of the northwestern Tethys (Mattsee, Austria). Austrian Journal of Earth Sciences. 104: 4-14. gs

Stainforth, R. M., Lamb, J. L., Luterbacher, H., Beard, J. H. & Jeffords, R. M. (1975). Cenozoic planktonic foraminiferal zonation and characteristics of index forms. University of Kansas Paleontological Contributions, Articles. 62: 1-425. gs O

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

Toumarkine, M. & Luterbacher, H. (1985). Paleocene and Eocene planktic foraminifera. In, Bolli, H. M., Saunders, J. B. & Perch-Neilsen, K. (eds) Plankton Stratigraphy. Cambridge Univ. Press, Cambridge 87-154. gs

Toumarkine, M. (1981). Discussion de la validité de l'espèce Hantkenina aragonensis, Nuttall, 1930; Description de Hantkenina nuttalli, n.sp. Cahiers de Micropaléontologie. 4: 109-119. gs


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

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