Hantkenina alabamensis Cushman 1925 from: Quilty, P.G.. (1976): Planctonic foraminifera DSDP Leg 34- Nazca Plata . DSDP initial reports Vol. 34 | . |
Notice: This catalogue page may contain unedited data.
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Species Hantkenina alabamensis Cushman 1925 |
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| Diagnosis / Definition: |
Pearson et al. (2006):
DESCRIPTION.
Type of wall: Smooth, normal perforate and
nonspinose; tubulospine surface imperforate, smooth or
with fine striations.
Test morphology: Planispiral, compact and
biumbilicate, with a quadrate or somewhat polygonal
peripheral outline; 5-6 closely appressed chambers in
the adult whorl, rounded to polygonal in shape and
moderately inflated, becoming globular in the final
stages; sutures depressed, slightly sigmoidal; umbilical
regions are deep and restricted; adult chambers extend
into a hollow tubulospine; primary aperture is a high
equatorial arch, narrow at the top, broadening at the base
into lateral lobes, bordered by an imperforate lip, often
crenulated and pustulose along the margin; pustules common on early chambers of the adult whorl and in the umbilical regions; tubulospines vary from long and slender to short and stout, arising sharply from the supporting chamber from a constricted base, straight and inclined forwards in the direction of coiling, almost tangential with respect to the shell periphery in a swastika-like arrangement, positioned at the anterior chamber edge, spanning the suture between chambers,
in contact with the posterior wall of the adjacent younger chamber along one third to one half of the length in final stages, distal ends taper to a point, blunt ended or terminating in a small coronet structure (Ramsay, 1962).
Size: Maximum diameter (excluding
tubulospines) 0.30-60 mm. |
| Discussion / Comments: |
Toumarkine & Luterbacher (1985):
Hantkenina alabamensis is the most advanced representative of the genus. Its chambers increase slowly in size and are closely pressed against each other The contour of the periphery is rounded.
H. longispina Cushman, 1925a (Fig. 25.11) has longer spines arranged in an apical position, whereas H. brevispina Cushman, 1925a (Fig. 25.12) differs only by the shorter and blunter spines. We include both species in the range of variability of H. alabamensis.
Van Eijden & Smit (1991):
Remarks. We found a single specimen in Sample 121-757B-14H-1, 110-115 cm.
Pearson et al. (2006):
DISTINGUISHING FEATURES.-
Hantkenina alabamensis can be distinguished from H. compressa by the greater lateral inflation of the final 1-2 chambers,
the more compact and involute coiling and more forward
leaning tubulospines. The species intergrades with H.
compressa at the beginning of its range, but H.
compressa appears stratigraphically lower and is closer
in morphology to H. dumblei. It differs from H. primitiva
in the greater lateral chamber inflation and by having a
full complement of tubulospines in the adult whorl, and
from H. nanggulanensis in the smaller size and absence
of extremely globular final chambers.
DISCUSSION.-
This is the most commonly recorded species of Hantkenina and has been used to present a wide range of morphologies. Under this taxonomy we follow a strict definition of H. alabamensis based on the distinctive holotype specimen that embodies the relatively inflated final chamber and a swastika-like
arrangement of tubulospines. We have included a variety
of specimens to show the range of variability permitted
to H. alabamensis (Pl. 8.4); some of these are close to
Hantkenina compressa (Pl. 8.4, Figs. 9, 10).
PHYLOGENETIC RELATIONSHIPS.-
Evolved from H. compressa in lower Zone E 1 3.
STRATIGRAPHIC RANGE.-
Lower Zone E1 3 to the Eocene/Oligocene boundary.
GEOGRAPHIC DISTRIBUTION.-
Worldwide, mid
to low latitudes in open ocean and shallower shelf sites.
STABLE ISOTOPE PALEOBIOL0GY.-
Hantkenina alabamensis registers negative ň18O and positive ň13C in multispecies isotopic analysis (Poore and Matthews, 1984; Boersma and others, 1987; Coxall and others, 2000; Pearson and others, 2001; Wade and Kroon, 2002) indicating that it lived in warm waters of the surface mixed layer.
Quilty (1976):
Remarks: Both species of Hantkenina identified here are identified on the characters of the spines. Both species occur only in one sample. Identifications at species level are tentative only. |
| Systematics: |
15
Classis Foraminifera
Genus Planorotalites
Species Hantkenina alabamensis
32
Ordo Foraminiferida
Familia Hantkeninidae
Genus Hantkenina
Species Hantkenina alabamensis
35
Ordo Foraminiferida
Superfamilia Globigerinaceae
Familia Hantkeninidae
Genus Clavigerinella
Genus Hantkenina
Species Hantkenina alabamensis
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| Synonym list: |
Toumarkine & Luterbacher (1985):
Van Eijden & Smit (1991):
Pearson et al. (2006):
1924 Hantkenina alabamensis Cushman. - Cushman : p.3 pl. 1, fig. 1-6;
pl. 2, fig. 5 [Eocene, Zeuglodon bed, Cocoa Post Office,
Alabama]
1939 Hantkenina alabamensis Cushman. - Rey : p.325 pl. XXII; fig. 17 [upper
Eocene and lower Oligocene, Nummulitique du Rharb,
Marocco]
1962 Hantkenina australis Finlay. - Ramsay : p.83 pl. 16; fig. 10 [middle Eocene, Kilwa Masoko area, Tanganyika];
[Not Finlay, 1939]
1969 Hantkenina suprasuturalis Brönnimann. - Samanta : pl. 3; fig. 2a [Globorotalia cerroazulensis Zone, Kopili Fm.,
Assam, India]
1988 Hantkenina suprasuturalis Brönnimann. - Coccioni : p.86 pl. 1, fig. 12-13;
pl. 2, fig. 1-8 [upper Eocene, Massignano stratotype
section, Italy]
non 1988 Hantkenina alabamensis Cushman. - Coccioni : p.85 pl. 1; fig. 1-9 [upper Eocene, Massignano stratotype section, Italy];[=Hantkenina primitiva]
2006 Hantkenina alabamensis Cushman. - Pearson et al. : p.227 pl. 8.4; fig. 1-16 (Pl. 8.4, Figs. 1-2: new SEMs of the holotype of
Hantkenina alabamensis Cushman)
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| Was used in synonym list of: |
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| Specimen: |
Cushman Collection - Smithsonian Museum of Natural History, Washington, D.C., Inventory number: USNM 35308
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| References: |
Cushman,J.A. (1924):
A new genus of Eocene foraminifera . Proceedings of the U.S. National Museum Vol. 66 p. 1-4
Cushman,J.A. (1925):
New foraminifera from the Upper Eocene of Mexico . Contributions from the Cushman Foundation for Foraminiferal Research Vol. 1 p. 4-9
Cushman,J.A. (1925):
A new genus of Eocene foraminifera . Proc. U.S. natl. Mus. Vol. 66 p. 1-4
Rey,M. (1939):
Distribution stratigraphique des Hantkenina dans le Nummulitique du Rharb (Maroc) . Bulletin de la Société Géologique de France Vol. 5 p. 321-341
Thalmann,H.E. (1942):
Foraminiferal genus Hantkenina and its subgenera . American Journal of Sciences Vol. 240 p. 809-823
Brönnimann,P. (1950):
The Genus Hantkenina Cushman in Trinidad and Barbados, B.W.I. . Journal of Paleontology Vol. 24 p. 397-420
Ramsay,W.R. (1962):
Hantkenininae in the Tertiary rocks of Tanganyika . Contributions from the Cushman Foundation for Foraminiferal Research Vol. 13 p. 79-89
Samanta,B.K. (1969):
Eocene planktonic foraminifera from the Gargo Hills, Assam, India . Micropalaeontology Vol. 15 p. 325-350
Quilty,P.G.. (1976):
Planctonic foraminifera DSDP Leg 34- Nazca Plata . DSDP initial reports Vol. 34
Toumarkine,M. and Luterbacher,H.P. (1985):
Paleocene and Eocene Planktic Foraminifera.
In: Plankton Stratigraphy p. 87-154
Coccioni,R. (1988):
The genera Hantkenina and Cribrohantkenina (Foraminifera) in the Massignano section (Ancona, Italy).
In: The Eocene-Oligocene Boundary in the Marche-Umbria Basin (Italy), Ancona International Subcommission on Paleogene Stratigraphy, Special Publication II Vol. 2 Eds: Premoli Silva, I.Coccioni, R.Montanari, A.. p. 81-96
Van Eijden,A.J.M. and Smit,J. (1991):
Eastern Indian Ocean Cretaceous and Paleogene quantitative biostratigraphy.
In: Proceedings of the Ocean Drilling Program, Scientific Results Vol. 121 Eds: Weissel, J.Peirce, J.Taylor, E.Alt, J. p. 77-123
Pearson,P.N.; Olsson,R.K.; Hemleben,C.; Huber,B.T. and Berggren,W.A. (2006):
Atlas of Eocene Planktonic Foraminifera. p. 1-513
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