Hantkenina nanggulanensis Hartono 1969 from: Pearson, P.N.Olsson, R.K.Hemleben, C.Huber, B.T.Berggren, W.A. (2006): Atlas of Eocene Planktonic Foraminifera. p. 1-513 | . |
Notice: This catalogue page may contain unedited data.
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Species Hantkenina nanggulanensis Hartono 1969 |
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| Diagnosis / Definition: |
Pearson et al. (2006):
DESCRIPTION.
Type of wall: Smooth, normal perforate and
probably nonspinose; tubulospines imperforate, smooth
or with fine striations.
Test morphology: Planispiral, biumbilicate,
strongly inflated and very large for the genus; 5-6 closely
appressed, spherical or polygonal chambers in the adult
whorl, increasing rapidly in size as added, becoming
highly inflated in the final stages; peripheral outline
(excluding tubulospines) is lobed or angular; adult
chambers extended into a hollow tubulospine; sutures
depressed and curved; umbilicus deep and restricted;
aperture shape is variable, laterally pinched into a narrow
slit with flaring basal lobes or open and triangular,
symmetrical (as is typical for-zarlier hantkeninids) or
asymmetrical, with folds and invaginations in the margin
and lip; tubulospines short and triangular or long and
slender, ends tapering to a point, positioned at the
anterior chamber edge, spanning the suture between
chambers; arising sharply from the supporting chamber
and inclined forward in the direction of coiling at a low
angle almost tangential with respect to the periphery in
the final stages and contacting adjacent younger
chambers along their outer periphery, penultimate
tubulospines may be completely enveloped by globular
younger chambers.
Size: Maximum diameter of the holotype
(excluding tubulospines) is 0.47 mm (Hartono, 1969). |
| Discussion / Comments: |
Pearson et al. (2006):
DISCUSSION.-
This morphospecies is transitional
between Hantkenina alabamensis and Cribrohantkenina
injlata. The chambers of the final whorl are highly
inflated, as in C. injlata, but the species lacks additional
area1 apertures. In some specimens the apertural opening and surrounding lip becomes irregularly folded and
invaginated to form lobes of the primary aperture (Pl.
8.1 1, Fig. 18), a condition that probably represents the
transition to the more complex multiple aperture system
of Cribrohantkenina. Formerly this morphotype has
usually been included in H. alabamensis; however, we
observe that it is stratigraphically and morphologically
distinct from the latter and thus merits specific status.
Bronnimann (1950) remarked in his distinction of H.
suprasuturalis that his species is generally larger and
much more inflated than H. alabamensis, suggesting
that it might be a prior synonym of H. nanggulanensis.
However, the holotype of H. suprasuturalis is a peculiar
specimen with a very angular peripheral outline and is
not the typical upper Eocene morphospecies we
recognise here as H. nanggulanensis, nor is it
significantly more inflated than the holotype of H.
alabamensis. The name nanggulanensis has rarely been
used outside its type locality. We have been unable to
study the holotype but the type illustrations are good
and we have collected comparable specimens from the
type Nanggulan Formation (see Plate 8.11).
PHYLOGENETIC RELATIONSHIPS.-
Evolved
from H. alabamensis by inflation of the chambers and
widening of the arched equatorial aperture in uppermost
Zone E13.
STRATIGRAPHIC RANGE.-
Late Eocene,
uppermost Zone E 13 to the Eocene/Oligocene boundary.
GEOGRAPHIC DISTRIBUTION.-
Worldwide, lowmid
latitude open-ocean and marginal
paleoenvironments.
STABLE ISOTOPE PALEOBIOLOGY.-
Pearson and
others (2001) recorded this species with isotopic values
intermediate between other CO-occurring species.
Hantkenina spp. analyzed together from Zone P15 have lower ō18O and higher ō13C than all other species
analyzed, suggesting a surface mixed-layer depth
habitat (Coxall and others, 2000). |
| Systematics: |
35
Ordo Foraminiferida
Superfamilia Globigerinaceae
Familia Hantkeninidae
Genus Hantkenina
Species Hantkenina nanggulanensis
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| Synonym list: |
Pearson et al. (2006):
1962 Hantkenina (Hantkenina) suprasuturalis Brönnimann. - Ramsay : p.85 pl. 16; fig. 12a-b, 13, 14, 18 [middle Eocene, Tanganyika, Samples WA 1960;
1963, Kilwa Masoko area]; [Not Brönnimann, 1950]
1969 Hantkenina nanggulanensis Hartono. - Hartono : p.154 pl. 20; fig. 3-4 [upper Eocene, Kebon Agung, Nanggulan
region, Java]
2006 Hantkenina nanggulanensis Hartono. - Pearson et al. : p.247 pl. 8.11; fig. 1-18 (Pl. 8.1 1, Figs. 1, 2: original illustration of the
holotype of Hantkenina nanggulanensis Hartono)
(Pl. 8.11, Fig. 3: original illustration of the paratype
of Hantkenina nanggulanensis Hartono)
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| Specimen: |
Paleontological Collection of the Geological Survey of Indonesia - Bandung, Inventory number: P.D. 5104
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| References: |
Ramsay,W.R. (1962):
Hantkenininae in the Tertiary rocks of Tanganyika . Contributions from the Cushman Foundation for Foraminiferal Research Vol. 13 p. 79-89
Hartono,H.M.S.. (1969):
Globigerina marls and their planktonic foraminifera from the Eocene of Nanggulan, Central Java . Contributions from the Cushman Foundation for Foraminiferal Research Vol. 20 p. 152-159
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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