Subbotina senni Beckmann 1953 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 Subbotina senni Beckmann 1953 |
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| Diagnosis / Definition: |
Pearson et al. (2006):
DESCRIPTION.-
Type of wall: Normal perforate, cancellate,
spinose, succulifer-type wall, in adult or terminal stage
covered by a thick calcite crust that closes off pores and
buries spines.
Test morphology: Test trochospiral, moderately
elevated initial whorl, globular, ovate to circular in
outline, chambers ovoid; in spiral view 4 globular,
slightly embracing chambers in ultimate whorl, increasing slowly in size, ultimate chamber may be equal
to or smaller in size than penultimate chamber, sutures
moderately depressed, straight; in umbilical view 3112 -4
globular, slightly embracing chambers, increasing
moderately in size, ultimate chamber may be equal to or
smaller in size than penultimate chamber, sutures
moderately depressed, straight; umbilicus small,
surrounded by heavy build-up of calcite crust, aperture
(when visible) umbilical, bordered by thickened rim; in
edge view moderately elevated trochospire, chambers
ovoid in shape, angled towards the umbilicus, somewhat
embracing.
Size: Maximum diameter 0.28-0.42 mm. |
| Discussion / Comments: |
Pearson et al. (2006):
DISTINGUISHING FEATURES.-
The species is
characterized by its globular test, thick calcite crust that
covers and closes pores, a moderately elevated
trochospire, and the heavy build-up of calcite crust
surrounding the umbilicus.
DISCUSSION.-
The thick calcite crust led Beckmann
(1953) to place his new species senni in the genus
Sphaeroidinella. Better understanding of the
stratigraphic range of planktonic foraminifera, leading
to the first detailed zonation of Paleogene and Neogene
sections in Trinidad by Bolli (1957) showed that
Sphaeroidinella was a Neogene genus. Bolli placed
Beckmann's species in Globigerina and showed that it
had a lower to middle Eocene range. Subsequently, senni
has been placed in Globigerinatheka (Fleisher, 1974),
tentatively in Subbotina (Poore and Brabb, 1977), and
in Muricoglobigerina (Blow, 1979). Bolli (1972) noted
fide Beckmann, 1971) the affinity of the thick wall
structure of Globigerina senni with Globigerinatheka
subconglobuta micra (Shutskaya), thereby suggesting
that the two species were phylogenetically related.
Forms identified as G. micra are small, heavily
encrusted, and lack identifiable supplementary apertures.
Lacking type material, we suggest that these forms are
small senni and that micra may be a junior synonym.
Globigerina orbformis Cole (a paratype here illustrated
in SEM, P1. 6.17, Figs. 5-7) may be a senior synonym
but it appears not well enough preserved to make a
positive determination and it has rarely been recorded
I in the literature.
Fleisher (1 974) noted in his study of senni from
the middle Eocene at DSDP Site 219, Arabian Sea, that
this species may be the direct ancestor of G. micra due
to the thickened crust-like wall and compact test, although he did not identify G. micra at Site 219. He
placed senni in Globigerinatheka, rather than in
Subbotina, due to the closer morphologic affinity ofsenni
to this genus, even though the species lacks accessory
apertures, a diagnostic feature of Globigerinatheku.
Fleisher (1974) described Subbotina kiersteadae from
the same section in which he identified senni and
regarded it as the ancestral species of G. senni. The
holotype of S. kiersteadae (Pl. 6.17, Fig. 16) is a
specimen from which the ultimate chamber is broken
off. When present it would have covered the umbilical
aperture as in senni. The test wall shows the typical
encrustation of senni surrounding the umbilicus. It is
here regarded as a junior synonym of senni. At Site 2 19
Fleisher recorded S. kiersteadae in Zones E8 and E9,
along with G. senni.
Blow (1979) erected the genus Muricoglobigerina
with Muricoglobigerina soldadoensis
soldadoensis (=Acarinina soldadoensis in this work) as
the type species. The diagnostic feature of Blow's new
genus was the 'murical-sheath', which he described as
due to the coalescence of muricae (individual conical
projections or pustules from the chamber wall). He
emphasized that the murical-sheath was a primary
structure and could not be considered as a "calcite crust" (1979, p. 412) or secondary structure caused by latestage
calcification. Acarininid taxa with murical-sheaths
were placed in Muricoglobigerina, whereas acarininid
taxa with individual, separated muricae (pustules)
covering the chamber walls were placed in Globorotuliu
(Acarinina). Furthermore, Blow regarded Muricoglobigerina
soldadoensis as directly ancestral to
Muricoglobigerina senni and used specimens identified
as senni to illustrate the murical-sheath. However most
of the specimens illustrated by Blow as
Muricoglobigerina senni are not this species, as it is clear
from his images (his pls. 131, 142, 146, 236) that he
selected heavily pustulose acarininid specimens in an
effort to demonstrate a relationship between these two
species.
In Acarinina pustules continue to enlarge and
coalesce during chamber growth and can form a dense
compact structure (the murical-sheath of Blow) in some
species. However, the thick wall of senni is due to an
additional layer or layers of calcite, thus forming a calcite
crust feature in the terminal stage of its life cycle. This
can be observed in Plate 6.17, Figs. 9, 10 that show calcification around spines and in Figs. 19,20 where it
can be observed that spines were completely buried by late-stage calcification. This feature can be often observed in extant species (Neoglobigerina dutertrei,
Sphaeroidinella dehiscens, deep-water Globorotalia etc.,
Hemleben and others, 1989).
This enigmatic species possesses the gross
morphology of Subbotina. Globular chambers are
arranged in a coil around a small umbilicus, the aperture
is umbilically directed, and the aperture is a small arch,
although without a distinct lip, bordered by a thin rim.
Thickening of the test wall by late-stage gametogenetic
calcification is not unusual in Eocene species of
Subbotina and extension of the ultimate chamber over
the umbilicus is also seen in the species S. angiporoides,
S. jacksonensis, and S. utilisindex.
PHYLOGENETIC RELATIONSHIPS.-
The origin of
Subbotina senni is uncertain but we suggest that S.
roesnaesensis is the most likely ancestor. Subbotina
senni has been suggested by ~ o l l(i1 972) as an ancestor
to the genus Globigerinatheka. Blow (1979) thought
that it might be an ancestor to Globigerinatheka index.
Following observations of wall texture and dissected
specimens of senni, Guembelitroides nuttalli and
globigerinathekides, we conclude that the most likely
ancestor of Globigerinatheka is G. nuttalli (see Chapter
7).
GEOGRAPHIC DISTRIBUTION.-
Global in low to mid latitudes.
STABLE ISOTOPE PALEOBIOL0GY.-
Subbotina
senni apparently occupied a mixed layer habitat (Pearson
and others, 1993,2001). It records more negative ò18O
values than do species of Catapsydrax, Hantkenina, and
other species of Subbotina. It is less enriched in ò13C
values than species of Acarinina and Morozovella.
Subbotina senni may have been a shallow mixed layer
species that sank to middle mixed layer or deeper depths
during gametogenesis. The isotope values may display
a shallow life style during the juvenile through preadult
stage and adding a calcite crust below the thermocline
(Pearson and others, 1993). |
| Systematics: |
35
Ordo Foraminiferida
Superfamilia Globigerinaceae
Familia Globigerinidae
Genus Subbotina
Species Subbotina yeguaensis
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| Synonym list: |
Pearson et al. (2006):
? 1927 Globigerina orbiformis Cole. - Cole : p.33 pl. 5; fig. 7 [middle
Eocene, Guayabal Fm., Tampico, Mexico]
1953 Sphaeroidinella senni Beckmann. - Beckmann : p.394 pl. 26; fig. 2-4; text-fig. 20 [middle Eocene, Mount Hillaby, Barbados]
1957 Globigerina senni Beckmann. - Bolli : p.163 pl. 35; fig. 10a-12 [middle Eocene Porticulasphaera mexicana Zone,
Navet Fm., Trinidad]
? 1958 Globigerinoides subconglobatus var. micra Shutskaya. - Shutskaya : p. 87-88 pl. 1; fig. 1 (holotype), 2, 3 [middle Eocene, associated with Globorotalia
aragonensis, Cherkesskiy horizon, Nagutskoye Well, N.
Caucasus]
1974 Globigerinatheka senni Beckmann. - Fleisher : p.1021 pl. 8; fig. 10, 11 [middle Eocene Zone E9, DSDP Site
2 19, Laccadive Ridge, eastern Arabian Sea]
? 1974 Subbotina kiersteadae Fleisher. - Fleisher : p.1032 pl. 16; fig. 1-9 [middle Eocene Zone E9, DSDP Site 219, Laccadive
Ridge, eastern Arabian Sea]
1975 Globigerina senni Beckmann. - Toumarkine : p.750 pl. 5; fig. 5-11 [figs. 5-8, middle Eocene, DSDP Site 305, Shatsky
Rise, northwest Pacific Ocean; figs. 9-1 1, middle Eocene,
DSDP Site 313, northeastern Mid-Pacific Mountains,
Central Pacific Ocean]
1977 "Subbotina" senni Beckmann. - Poore & Brabb : p.269 pl. 3; fig. 12-14 [middle Eocene, Twobar Shale,
San Lorenzo Fm., Santa Cruz Mountains, California]
1978 Globigerina senni Beckmann. - Toumarkine : p.718 pl. 10; fig. 10-14 [middle Eocene, Angola Basin, DSDP Site 364,
southeastern South Atlantic Ocean]
p 1979 Muricoglobigerina senni Beckmann. - Blow : p.1131 pl. 165; fig. 8 (partim; not pl. 131: Figs. 7-9; pl. 142: figs. 7,9; pl. 146:
figs. 9, 10; pl. 236: Figs. 1-4.); [middle Eocene Zone E8, Kane 9, core 42, Endeavour
Seamount, equatorial Atlantic Ocean]
1983 Globigerinatheka senni Beckmann. - Pujol : p.651 pl. 6; fig. 3 [lower Eocene Zone E7, DSDP Hole
5 15B, Brazil Basin, South Atlantic Ocean]
1985 Globigerina senni Beckmann. - Toumarkine & Luterbacher : p.127 fig. 28, 1-5 (fig. 28, la-c,
reillustration of holotype, pl. 26: fig. 2a-c);
fig. 28, 2, 3 [middle Eocene Orbulinoides beckmanni Zone, Navet Fm., Trinidad];
fig. 28, 4, 5 (reillustration of Toumarkine, 1975,
pl. 5: figs. 9, 10)
2001 Muricoglobigerina senni Beckmann. - Warraich & Ogasawara : p.42 fig. 11: 6-8 [Zone E1011 1, Kirthar
Fm., Snlaiman Range, Pakistan]
2004 Subbotina senni Beckmann. - Pearson et al. : [lower Eocene Zone P819, Tanzania]
2006 Subbotina senni Beckmann. - Pearson et al. : p.151 pl. 17; fig. 1-20 (Pl. 6.17, Figs. 1-3: new SEMs of holotype of
Sphaeroidinella senni Beckmann)
(Pl. 6.17, Figs. 5-7: new SEMs of holotype of
Globigerina orbiformis Cole)
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| References: |
Cole,W.S. (1927):
A foraminiferal fauna from the Guabal Formation in Mexico . Bulletins of American paleontology Vol. 14 p. 1-46
Beckmann,J.P. (1953):
Die Foraminiferen der Oceanic Formation (Eocaen-Oligocaen) von Barbados, Kl. Antillen . Ecoglae geologicae Helvetiae Vol. 46 p. 301-412
Bolli,H.M. (1957):
Planktonic Foraminifera from the Eocene Navet and San Fernando formations of Trinidad, B.W.I. . Bull. U.S. natl. Mus. Vol. 215 p. 155-172
Shutskaya,E.K. (1958):
Izmenchivosti nekotorikh nizhnepaleogenovikh plannktonikh foraminifer severnogo Kavkaza [Variations of some lower Paleogene planktonic foraminifers of the northern Caucasus] . Akademy Nauk SSSR Voprosy Mikropaleontologii Vol. 2 p. 84-90
Fleisher,R.L. (1974):
Cenozoic planktonic foraminifera and biostratigraphy, Arabian Sea, Deep Sea Drilling Project, Leg 23A.
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Middle and Late Eocene planktonic foraminifera from the northwestern Pacific, Leg 32 of the Deep Sea Drilling Project.
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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
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Eocene and Oligocene planktonic foraminifera from the Upper Butano Sandstone and type San Lorenzo Formation, Santa Cruz Mountains, California . Journal of Foraminiferal Research Vol. 7 p. 249-272
Toumarkine,M. (1978):
Planktonic Foraminiferal Biostratigraphy of the Paleogene of Sites 360 to 364 and the Neogene of Sites 362A, 363, and 364 Leg 40.
In: Initial Results of the Deep Sea Drilling Project Vol. 40
Blow,W.H. (1979):
The Cainozoic Globigerinida. 3 Vols p. 1413 pp
Pujol,C. (1983):
Cenozoic Planktonic Foraminiferal Biostratigraphy of the Southwestern Atlantic (Rio Grande Rise): Deep Sea Drilling Project Leg 72.
In: Initial Reports of the Deep Sea Drilling Project Vol. 72 Eds: Barker, P.F.Johnson, D.A. p. 623-673
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Paleocene and Eocene Planktic Foraminifera.
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Upper Campanian-Paleocene foraminifera from the James Ross Island region (Antarctic Peninsula).
In: Geology and Paleontology of Seymour Island, Antarctica, Memoirs of the Geological Society of America Vol. 169 Eds: Feldmann, R.M..Woodburne, M.O.. p. 163-251
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Tethyan Paleocene-Eocene planktic foraminifera from the Rakhi Nala and Zinda Pir land sections of the Sulaiman Range, Pakistan . Science Reports of the Institute of Geoscience University of Tsukuba, section B Vol. 22 p. 1-59
Pearson,P.N.; Nicholas,C.J..; Singano,J.M..; Bown,P.R..; Coxali,H.K..; van Dongen,B.E..; Huber,B.T.; Karega,A..; Lees,J.A..; Misaky,E..; Pancost,R.D..; Pearson,M.. and Roberts,A.P.. (2004):
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Atlas of Eocene Planktonic Foraminifera. p. 1-513
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