Hantkeninaalabamensis Cushman.—Raju, 1968:291, pl. 1: fig. 11 [upper Eocene Turborotaliacerroazulensis Zone, Cauvery Basin, India].—Rey, 1939:325, pl. XXII: fig. 13 [upper Eocene and lower Oligocene, Nummulitique du Rharb, Morocco]. [Not Cushman, 1924.]
Hantkenina (Hantkenina) primitiva Cushman.—Blow, 1979:1161, pl. 243: fig.4 [upper Eocene, Zone P16, Lindi, Tanzania]. [Not Cushman and Jarvis, 1929.]
Hantkenina cf. dumblei Weinzierl and Applin. —Coccioni, 1988:85, pl. 1: figs. 10-11 [upper Eocene, Zone P16, Massignano, Italy]. [Not Weinzierl and Applin, 1929.]
Taxonomic discussion: Hantkeninacompressa is intermediate in morphology between H. dumblei and H. alabamensis and overlaps stratigraphically with them both. It thus bridges the supposed evolutionary gap (Blow, 1979) between middle and late Eocene hantkeninids. This morphotype is common in deep sea and land-outcropping pelagic sections but has previously been referred to H. dumblei, H. cf. dumblei or H. alabamensis, which has had the effect of artificially extending the stratigraphic range of H. dumblei into the upper Eocene and lowering the range of H. alabamensis within the middle Eocene. Recognition of H. compressa demands stricter definitions of the latter two species and increases their biostratigraphic utility. The species intergrades with H. alabamensis in the upper Eocene. We have included specimens that are transitional to H. alabamensis to show the range of variability permitted to Hantkeninacompressa (Pl.8.6, Figs. 10, 14, 21). The holotype of H. brevispina Cushman, 1924, which is described as having much shorter and stouter tubulospines than other hantkeninids, resembles Parr’s (1947) illustrations of H. compressa and may be a prior synonym. The holotype of H. brevispina, however, is missing from the USNM collections and thus unavailable for comparison. We suggest, therefore, that H. brevispina should be suppressed and H. compressa adopted as the valid name for these morphotypes. [Coxall & Pearson 2006]
Distinguishing features: Parent taxon (Hantkenina): Final chambers with tubulospines This taxon: Final chambers triangular, with nearly continuous peripheral outline; tubulospines in the trans-sutural position and with forward-inclined orientation.
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.
Description
Morphology: Planispiral, biumbilicate, somewhat compressed laterally, although individual chambers are slightly inflated; 5-6 closely appressed chambers in the final whorl, increasing rapidly in size as added, sub-triangular or polygonal in shape; adult chambers extend into a hollow tubulospine; peripheral outline continuous, lobed or slightly angular; aperture is an elongated narrow equatorial arch flaring into lateral lobes, bordered by a wide flaring lip; sutures straight to slightly sigmoidal; tubulospines straight, long and slender or short and triangular, arising sharply from the supporting chamber, positioned at the anterior chamber edge, spanning the suture between adjacent chambers, in contact with the posterior wall of the next youngest chamber along a short portion of the length at the base, inclined forward in the direction of coiling, distal ends taper to points, often with a small coronet structure (Ramsay, 1962), sometimes opening from the axial canal into a small terminal aperture. [Coxall & Pearson 2006] Wall type: Smooth, perforate and probably nonspinose; tubulospines imperforate, smooth or with fine striations. [Coxall & Pearson 2006] Size: Maximum diameter (excluding tubulospines) 400-700 µm. [Coxall & Pearson 2006]
Character matrix
test outline:
Lobate
chamber arrangement:
Planispiral
edge view:
Compressed
aperture:
Terminal
sp chamber shape:
Subtriangular
coiling axis:
N/A
periphery:
Tubulospines
aperture border:
Thick lip
umb chbr shape:
Subtriangular
umbilicus:
Wide
periph margin shape:
Subangular
accessory apertures:
None
spiral sutures:
Moderately depressed
umb depth:
Shallow
wall texture:
Smooth
shell porosity:
Finely Perforate: 1-2.5µm
umbilical or test sutures:
Moderately depressed
final-whorl chambers:
5-6
N.B. These characters are used for advanced search. N/A - not applicable
Biogeography and Palaeobiology
Geographic distributionWorldwide at low to mid latitudes, also New Zealand. [Coxall & Pearson 2006]
Aze et al. 2011 summary: Low to middle latitudes; based on Coxall & Pearson (2006) Isotope paleobiologyHantkeninacompressa from Zone E12 registers relatively low δ18O and high δ13C, similar to coexisting Morozovelloides and Acarinina (Coxall and others, 2000), indicating that it lived in warm waters of the surface mixed layer. There is no δ13C -enrichment trend with increasing test size. [Coxall & Pearson 2006] Aze et al. 2011 ecogroup 2 - Open ocean mixed-layer tropical/subtropical, without symbionts. Based on _13C lighter than species with symbionts; also with relatively light _18O. Sources cited by Aze et al. 2011 (appendix S3): Coxall & Pearson (2006) Phylogenetic relationsEvolved from H. dumblei by a reduction in chamber height and tightening of the planispiral coiling. [Coxall & Pearson 2006]
Geological Range: Notes: Mid Zone E11 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): in upper part of E11 zone (60% up, 41Ma, in Bartonian stage). Data source: Coxall & Pearson (2006), fig. 8.1
Plot of occurrence data:
Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
Triangles indicate an event for which a precise placement has been suggested
Histogram - Neptune occurrence data from DSDP and ODP proceedings. Pale shading <50 samples in time bin. Interpret with caution & read these notes
Taxon plotted: Hantkenina compressa, synonyms included - Hantkenina compressa;
Primary source for this page: Coxall & Pearson 2006 - Eocene Atlas, chap. 8, p. 233
References:
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 . (2): 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. gsO
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
Cushman, J. A. & Jarvis, P. W. (1929). New foraminifera from Trinidad. Contributions from the Cushman Laboratory for Foraminiferal Research. 5: 6-17. gs
Parr, W. J. (1947). An Australian Record of the Foraminiferal Genus Hantkenina. Proceedings of the Royal Society of Victoria. LVIII(I-II): 45-47. 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
Postuma, J. A. (1971). Manual of planktonic foraminifera. Elsevier for Shell Group, The Hague. 1-406. 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
Weinzierl, L. L. & Applin, E. R. (1929). The Claiborne Formation on the Coastal Domes. Journal of Paleontology. 3(4): 384-410. gs
Hantkenina compressa compiled by the pforams@mikrotax project teamviewed: 16-1-2025
Eocene_Atlas_pl08-6_fig11-13.jpg
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Postuma 1971 p227-4.JPG
Postuma 1971 p227-7.JPG
holotype: H. alabamensis compressa
