Parasubbotina griffinae Blow 1979 from: Pearson, P.N.Olsson, R.K.Hemleben, C.Huber, B.T.Berggren, W.A. (2006): Atlas of Eocene Planktonic Foraminifera. p. 1-513 | . |
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Species Parasubbotina griffinae Blow 1979 |
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| Diagnosis / Definition: |
Pearson et al. (2006):
DESCRIPTION.
Type of wall: Normal perforate, high porosity,
reticulated Clavigerinella-type, spinose.
Test morphology: Very low trochospiral,
globular, lobulate in outline, chambers globular, much
inflated; in spiral view 4-5 globular, somewhat
embracing chambers in ultimate whorl, increasing
moderately in size, inner whorl of chambers partly
overlapped by the ultimate whorl, sutures moderately
depressed, straight, penultimate and ultimate chamber
may be reduced in size relative to preceeding chambers;
in umbilical view 4-5 globular, somewhat embracing
chambers, increasing moderately in size, sutures
moderately depressed, straight, umbilicus a small sized
opening, enclosed by surrounding chambers, aperture
umbilical-extraumbilical, bordered by a narrow
continuous, lip or thickened rim; in edge view chambers
globular in shape, aperture a low arch extending midway
onto the peripheral edge, bordered by a narrow lip or
thickened rim.
Size: Maximum diameter of holotype 0.4 1 mm,
thickness 0.29 mm. |
| Discussion / Comments: |
Pearson et al. (2006):
DISTINGUISHING FEATURES.- Parasubbotina
griffinae is distinguished by its very low trochospiral,
globular test with strongly inflated chambers, with the
inner whorls partially overlapped by the ultimate whorl,
and the high porosity, reticulated Clavigerinella-type
wall texture.
DISCUSSION.- When Blow (1 979) described
Globorotalia (Turborotalia) griffinae (=Parasubbotina
griffinae), he selected the holotype and some paratypes
from the same sample (KANE 9 Core 42,200 cm) from
which he also illustrated hypotypic specimens of
Pseudoglobigerinella bolivariana (Petters). His case for
regarding griffinae as ancestral to bolivariana is clear
from the SEM illustrations of the two species (his pl.
150, figs. 1-9) as they both share a Clavigerinella-type
reticulate wall texture. Blow also illustrated paratypes
of P. griffinae from other levels in KANE 9 Core 42 (his
pl. 157, fig. 7, from 95 cm; pl. 162, figs. 8, 9, from 42
cm; pl. 165, figs. 1-3, from 15 cm) that clearly differ
from the holotype and paratypes of the species illustrated
from the type level. These paratypes have a more
coarsely cancellate, non-reticulate wall texture and a
thickened, continuous apertural lip. Toumarkine and
Luterbacher (1985) included morphotypes like these in
griffinae (their fig. 27:19-23). We place all these in
Paragloborotalia griffinoides n. sp. (see discussion under
that species).
Although not readily recognized by previous
workers, P griffinae appears in the stratigraphic record
shortly before the development of Pseudoglobigerinella
bolivariana and can be considered an intermediate
morphotype linking P. inaequispira and P. bolivariana.
We have also found specimens attributable to P. griffinae
as high as Zone E14 in Java (Pl. 5.10, Figs. 9-11)
although we recognize that detailed stratigraphic
investigations may reveal these forms, which are less
inflated than the holotype, not to be conspecific.
Globigerina micropora de Klasz, Le Calvez and
Rerat appears from the type illustration to have the gross
test morphology of grffinae but the character of the
aperture and wall texture cannot be determined.
PHYLOGENETIC RELATIONSHIPS.- Parasubbotina
griffinae evolved from P. inaequispira and
rapidly gave rise to Pseudoglobigerinella bolivariana.
GEOGRAPHIC DISTRIBUTION.- Global in low to
mid latitudes, P griffinae is a common constituent of
relatively high productivity environments in the Eocene.
STABLE ISOTOPIC PALEOBIOL0GY.- Relatively
heavy ò18O indicating cool water (H. K. Coxall,
unpublished data).
REPOSITORY.- Holotype and paratypes deposited in
the British Museum of Natural History, London. |
| Systematics: |
35
Ordo Foraminiferida
Superfamilia Globigerinaceae
Familia Globigerinidae
Genus Parasubbotina
Species Parasubbotina inaequispira
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| Synonym list: |
Pearson et al. (2006):
? 1969 Globigerina micropora de Klasz et al.. - De Klasz et al. : p.278 pl. 2; fig. 5a-c [lower middle Eocene Amiba
Fm., Gabon]
p 1979 Globorotalia (Turborotalia) griffinae Blow. - Blow : p.1072 pl. 96; fig. 5-9 (fig. 8 = holotype) (not pl. 157, fig.
7; pl. 162, figs. 8,9; pl. 165, figs. 1-3 =Paragloborotalia
griffinoides Olsson and Pearson, n. sp.) [lower Eocenc
Zone E7, KANE 9-Core 42, Endeavour Seamount,
equatorial Atlantic Ocean].
p 1985 Turborotalia griffininae Blow. - Toumarkine & Luterbacher : p.127 fig. 27: 13-17 (not fig. 27: 18-23.)
[reillustration of holotype and paratypes].
2006 Parasubbotina griffinae Blow. - Pearson et al. : p.90 pl. 5.10; fig. 1-15 (Pl. 5.10, Figs. 1-4: reillustration of holotype and paratypes of Globorotalia (Turborotalia) griffinae Blow
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| References: |
De Klasz,I.; Le Calvez,Y.. and Rerat,D.. (1969):
Nouveaux foraminiferes du bassin sedimentaire du Gabon (Afrique Equatoriale) . Proceedings of the III Congres Africaine de Micropaleontologie (Cairo, 1968) p. 269-287
Blow,W.H. (1979):
The Cainozoic Globigerinida. 3 Vols p. 1413 pp
Toumarkine,M. and Luterbacher,H.P. (1985):
Paleocene and Eocene Planktic Foraminifera.
In: Plankton Stratigraphy p. 87-154
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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