Planoglobanomalina pseudoalgeriana Olsson & Hemleben 2006 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 Planoglobanomalina pseudoalgeriana Olsson & Hemleben 2006 |
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| Diagnosis / Definition: |
Pearson et al. (2006):
DESCRIPTION.
Type of wall: Smooth, normal perforate. Well-preserved
specimens show smooth calcite overgrowths
on the umbilical shoulders of chambers and similar
irregular, discontinuous smooth bands on the test
periphery.
Test morphology: Test asymmetrical to fully
planispiral, compressed, loosely coiled, evolute, oval in
outline, chambers compressed, distinctly elongate; inner
spire of chambers visible due to loose coiling, 9-10
chambers in ultimate whorl, increasing gradually in size, last three chambers in ultimate whorl arranged in an
uncoiling trend, sutures slightly depressed, straight to
moderately curved, umbilicus moderate in size, circular
in shape, apertural lips of ultimate chamber and previous
chambers fuse to form a somewhat broad shelf that
extends around the umbilicus, relict apertures present
where apertural lips are not completely fused; in edge
view primary aperture equatorial, asymmetric, an ovalshaped
opening bordered by a broad lip, test much
compressed with a pinched periphery which gives the
chambers an ogival shape
Size: Maximum diameter of holotype 0.39 mm,
thickness 0.12 mm. |
| Discussion / Comments: |
Pearson et al. (2006):
ETYMOLOGY.-
Named for its resemblance to
Globigerinelloides algerianus Cushman and ten Dam.
DISTINGUISHING FEATURES.-
The most
distinguishing feature of Planoglobanomalina
pseudoalgeriana n. sp. is the remarkable homeomorphy
it shows with the upper Aptian planktonic foraminifer
Globigerinetloides algerianus Cushman and ten Dam
(1948) from which its name is derived. The test of P.
pseudoalgeriana n. sp. is loosely coiled, evolute, and
much compressed with 9-10 chambers in the ultimate
whorl and with the last three chambers showing a trend
towards uncoiling. Globanomalina is trochospiral,
tightly coiled, has few chambers in the ultimate whorl,
and an extraumbilical aperture confined to the umbilical
side.
DISCUSSION.-
Planoglobanomalina pseudoalgeriana
n. sp. is the type species for the new genus
Planoglobanomalina. Blow referred morphotypes from
a North Atlantic core to the Eocene/Oligocene planispiral
genus Pseudohastigerina and stated that the genus had
a polyphyletic origin, first appearing at the beginning of
the Eocene and again in the early Eocene Zone P9. We believe that Blow's observations are correct in as much
as we have observed a similar relationship in Zone E6
in the western North Pacific ODP Hole 865B and are
the basis for this new species. Hillebrandt (1976) was
first to illustrate this species (identified as P. micra) in
Zone E7 from southeastern Spain.
PHYLOGENETTC RELATIONSHIPS.-
Planoglobanomalina
pseudoalgeriana n. sp. evolved from
Globanomalina planoconica in Zone E6.
STRATIGRAPHIC RANGE.-
Zone E6 to Zone E8.
GEOGRAPHlC DISTRIBUTION.-
The occurrence
of this species in southeastern Spain, Tanzania, North
Atlantic Ocean, and at ODP Hole 865B, western North
Pacific Ocean suggests that it was widespread in low to
mid latitudes.
STABLE ISOTOPE PALEOBIOL0GY.-
No data
available |
| Systematics: |
35
Ordo Foraminiferida
Superfamilia Globigerinaceae
Familia Hedbergellidae
Genus Planoglobanomalina
Species Planoglobanomalina pseudoalgeriana
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| Synonym list: |
Pearson et al. (2006):
1976 Pseudohastigerina micra Cole. - Hillebrandt : p.337 pl. 4; fig. 16, 17 [lower Eocene Globorotalia palmerae Zone,
southeastern Spain]
p 1979 Pseudohastigerina danvillensis Howe & Wallace. - Blow : p.1181 pl. 159, fig. 6-7;
pl. 161, fig. 2-7;
pl. 166, fig. 2-10 (not pl. 166, fig. 8-10; pl. 253: fig.
10-12); [middle Eocene Zone P1 0, KANE 9-Core 42,
equatorial Atlantic Ocean];
[Not Howe and Wallace, 1932]
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| Specimen: |
Smithsonian Museum of Natural History, Washington, D.C., Inventory number: USNM 523183
Smithsonian Museum of Natural History, Washington, D.C., Inventory number: USNM 523184
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| References: |
Hillebrandt,A. (1976):
Los formainiferos planctonicos, nummulitidos y coccolitoforidos de las zona de Globorotalia palmerae del Cuisiense (Eoceno inferior) en el ES de Espana (Provincias de Murcia y Alicante) . Revista Espanol de Micropaleontologia Vol. 8 p. 323-394
Blow,W.H. (1979):
The Cainozoic Globigerinida. 3 Vols p. 1413 pp
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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